National Library of Energy BETA

Sample records for high purity germanium

  1. Use of a High-Purity Germanium Semiconductor Detector for Rapid Post-Nuclear Event Forensics 

    E-Print Network [OSTI]

    Horowitz, Steven Michael

    2015-07-27

    This thesis investigates the ability of a high-purity germanium detector to perform post-detonation forensics on the debris from several types of nuclear weapons 24 hours after detonation. The ultimate result of this ...

  2. Operation of a high purity germanium crystal in liquid argon as a Compton suppressed radiation spectrometer

    E-Print Network [OSTI]

    John L. Orrell; Craig E. Aalseth; John F. Amsbaugh; Peter J. Doe; Todd W. Hossbach

    2006-10-11

    A high purity germanium crystal was operated in liquid argon as a Compton suppressed radiation spectrometer. Spectroscopic quality resolution of less than 1% of the full-width half maximum of full energy deposition peaks was demonstrated. The construction of the small apparatus used to obtain these results is reported. The design concept is to use the liquid argon bath to both cool the germanium crystal to operating temperatures and act as a scintillating veto. The scintillation light from the liquid argon can veto cosmic-rays, external primordial radiation, and gamma radiation that does not fully deposit within the germanium crystal. This technique was investigated for its potential impact on ultra-low background gamma-ray spectroscopy. This work is based on a concept initially developed for future germanium-based neutrinoless double-beta decay experiments.

  3. Search of Axions from a Nuclear Power Reactor with a High-Purity Germanium Detector

    E-Print Network [OSTI]

    H. M. Chang; TEXONO Collaboration

    2007-01-21

    A search of axions produced in nuclear transitions was performed at the Kuo-Sheng Nuclear Power Station with a high-purity germanium detector of mass 1.06 kg at a distance of 28 m from the 2.9 GW reactor core. The expected experimental signatures were mono-energetic lines produced by their Primakoff or Compton conversions at the detector. Based on 459.0/96.3 days of Reactor ON/OFF data, no evidence of axion emissions were observed and constraints on the couplings $\\gagg$ and $\\gaee$ versus axion mass $m_a$ within the framework of invisible axion models were placed. The KSVZ and DFSZ models can be excluded for 10^4 eV < m_a < 10^6 ~eV. Model-independent constraints on \\gagg \\gv1 < 7.7 X 10^{-9} GeV^{-2} for m_{a} < 10^5 eV and \\gaee \\gv1 < 1.3 X 10^{-10} for m_{a} < 10^6 eV at 90% confidence level were derived. This experimental approach provides a unique probe for axion mass at the keV--MeV range not accessible to the other techniques.

  4. DEEP LEVEL TRANSIENT SPECTROSCOPY OF HIGH-PURITY GERMANIUM DIODES/DETECTORS

    E-Print Network [OSTI]

    Haller, E.E.

    2011-01-01

    1978 LBL,-3140"'/ c-. cr DEEP LEVEL TRANSIENT SPECTROSCOPY.are changing the charge state of deep traps. A minority trapenergy and concentration of deep traps in high-purity Ge, it

  5. Search of Axions at the Kuo-Sheng Nuclear Power Station with a High-Purity Germanium Detector

    E-Print Network [OSTI]

    Chang, C M; Chou, M H; Deniz, M; Huang, H X; Lee, F S; Li, H B; Li, J; Liao, H Y; Lin, S T; Singh, V; Wu, S C; Xin, B; al, et

    2006-01-01

    A search of axions produced in nuclear transitions was performed at the Kuo-Sheng Nuclear Power Station with a high-purity germanium detector of mass 1.06 kg at a distance of 28 m from the 2.9 GW reactor core. The experimental signatures were mono-energetic lines produced by their Primakoff or Compton conversions at the detector. No evidence of axion emissions were observed and model-independent constraints on the axion mass $m_a$, branching ratio $\\braxion$, and couplings $\\gagg$, $\\gaee$ were placed. Limits on $\\gagg ^2 \\braxion

  6. Characteristics of Signals Originating near the Lithium-Diffused N+ Contact of High Purity Germanium P-Type Point Contact Detectors

    SciTech Connect (OSTI)

    Aguayo, E. [Pacific Northwest National Laboratory (PNNL); Amman, M. [Lawrence Berkeley National Laboratory (LBNL); Avignone, F. T. [University of South Carolina/ORNL; Barabash, A.S. [Institute of Theoretical & Experimental Physics, Moscow, Russia; Barton, P. J. [Lawrence Berkeley National Laboratory (LBNL); Beene, James R [ORNL; Bertrand Jr, Fred E [ORNL; Boswell, M. [Los Alamos National Laboratory (LANL); Brudanin, V. [Joint Institute for Nuclear Research, Dubna, Russia; Busch, M. [Duke University; Chan, Y-D [Lawrence Berkeley National Laboratory (LBNL); Christofferson, C. D. [South Dakota School of Mines & Technology, Rapid City, SD; Collar, Juan I. [University of Chicago; Combs, D. C. [University of North Carolina / Triangle Universities Nuclear Lababoratory, Durham; Cooper, Reynold J [ORNL; Detwiler, J.A. [Lawrence Berkeley National Laboratory (LBNL); Doe, P. J. [University of Washington; Efremenko, Yuri [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Egorov, V. [Joint Institute for Nuclear Research, Dubna, Russia; Ejiri, H. [Osaka University; Elliott, S. R. [Los Alamos National Laboratory (LANL); Esterline, J. [Duke University; Fast, J.E. [Pacific Northwest National Laboratory (PNNL); Fields, N. [University of Chicago; Finnerty, P. [University of North Carolina / Triangle Universities Nuclear Lababoratory, Durham; Fraenkle, F. M. [University of North Carolina / Triangle Universities Nuclear Lababoratory, Durham; Galindo-Uribarri, Alfredo {nmn} [ORNL; Gehman, V. M. [Los Alamos National Laboratory (LANL); Giovanetti, G. K. [Univ, of North Carolina & Triangle Universities Nucl. Lab - Durham, NC; Green, M. P. [University of North Carolina / Triangle Universities Nuclear Lababoratory, Durham; Guiseppe, V.E. [University of South Dakota; Gusey, K. [Joint Institute for Nuclear Research, Dubna, Russia; Hallin, A. L. [University of Alberta, Edmonton, Canada; Hazama, R. [Osaka University; Henning, R. [Univ, of North Carolina & Triangle Universities Nucl. Lab - Durham, NC; Hoppe, E.W. [Pacific Northwest National Laboratory (PNNL); Horton, M. [South Dakota School of Mines & Technology, Rapid City, SD; Howard, S. [South Dakota School of Mines and Technology; Howe, M. A. [University of North Carolina / Triangle Universities Nuclear Lababoratory, Durham; Johnson, R. A. [University of Washington, Seattle; Keeter, K.J. [Black Hills State University, Spearfish, SD; Kidd, M. F. [Los Alamos National Laboratory (LANL); Knecht, A. [University of Washington, Seattle; Kochetov, O. [Joint Institute for Nuclear Research, Dubna, Russia; Konovalov, S.I. [Institute of Theoretical & Experimental Physics, Moscow, Russia; Kouzes, R. T. [Pacific Northwest National Laboratory (PNNL); LaFerriere, B. D. [Pacific Northwest National Laboratory (PNNL); Leon, J. [University of Washington, Seattle; Leviner, L. E. [University of North Carolina / Triangle Universities Nuclear Lababoratory, Durham; Loach, J.C. [Lawrence Berkeley National Laboratory (LBNL); Looker, Q. [Lawrence Berkeley National Laboratory (LBNL); Luke, P.N. [Lawrence Berkeley National Laboratory (LBNL); MacMullin, S. [University of North Carolina / Triangle Universities Nuclear Lababoratory, Durham; Marino, M. G. [University of Washington, Seattle; Martin, R.D. [Lawrence Berkeley National Laboratory (LBNL); Merriman, J. H. [Pacific Northwest National Laboratory (PNNL); Miller, M. L. [University of Washington, Seattle; Mizouni, L. [PPNL/Univ. of South Carolina; Nomachi, M. [Osaka University; Orrell, John L. [Pacific Northwest National Laboratory (PNNL); Overman, N. R. [Pacific Northwest National Laboratory (PNNL); Perumpilly, G. [University of South Dakota; Phillips II, D. G. [University of North Carolina / Triangle Universities Nuclear Lababoratory, Durham; Poon, A.W.P. [Lawrence Berkeley National Laboratory (LBNL); et al.

    2013-01-01

    A study of signals originating near the lithium-diffused n+ contact of p-type point contact (PPC) high purity germanium detectors (HPGe) is presented. The transition region between the active germanium and the fully dead layer of the n+ contact is examined. Energy depositions in this transition region are shown to result in partial charge collection. This provides a mechanism for events with a well defined energy to contribute to the continuum of the energy spectrum at lower energies. A novel technique to quantify the contribution from this source of background is introduced. Experiments that operate germanium detectors with a very low energy threshold may benefit from the methods presented herein.

  7. Pulse shapes from electron and photon induced events in segmented high-purity germanium detectors

    E-Print Network [OSTI]

    I. Abt; A. Caldwell; K. Kröninger; J. Liu; X. Liu; B. Majorovits

    2007-04-23

    Experiments built to search for neutrinoless double beta-decay are limited in their sensitivity not only by the exposure but also by the amount of background encountered. Radioactive isotopes in the surrounding of the detectors which emit gamma-radiation are expected to be a significant source of background in the GERmanium Detector Array, GERDA. Methods to select electron induced events and discriminate against photon induced events inside a germanium detector are presented in this paper. The methods are based on the analysis of the time structure of the detector response. Data were taken with a segmented GERDA prototype detector. It is shown that the analysis of the time response of the detector can be used to distinguish multiply scattered photons from electrons.

  8. Search of Neutrino Magnetic Moments with a High-Purity Germanium Detector at the Kuo-Sheng Nuclear Power Station

    E-Print Network [OSTI]

    H. T. Wong; TEXONO Collaboration

    2006-11-14

    A search of neutrino magnetic moments was carried out at the Kuo-Sheng Nuclear Power Station at a distance of 28 m from the 2.9 GW reactor core. With a high purity germanium detector of mass 1.06 kg surrounded by scintillating NaI(Tl) and CsI(Tl) crystals as anti-Compton detectors, a detection threshold of 5 keV and a background level of 1 $\\cpd$ near threshold were achieved. Details of the reactor neutrino source, experimental hardware, background understanding and analysis methods are presented. Based on 570.7 and 127.8 days of Reactor ON and OFF data, respectively, at an average Reactor ON electron anti-neutrino flux of $\\rm{6.4 \\times 10^{12} cm^{-2} s^{-1}}$, the limit on the neutrino magnetic moments of $\\rm{\\munuebar < 7.4 \\times 10^{-11} \\mub}$ at 90% confidence level was derived. Indirect bounds on the $\

  9. High Purity Germanium Detectors at LBNL | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLosThe23-24, 2011 High Energy Physics AdvisoryScienceHeavy-Ions|

  10. Neutron Damage in Mechanically-Cooled High-Purity Germanium Detectors for Field-Portable Prompt Gamma Neutron Activation Analysis (PGNAA) Systems

    SciTech Connect (OSTI)

    E.H. Seabury; C.J. Wharton; A.J. Caffrey; J.B. McCabe; C. DeW. Van Siclen

    2013-10-01

    Prompt Gamma Neutron Activation (PGNAA) systems require the use of a gamma-ray spectrometer to record the gamma-ray spectrum of an object under test and allow the determination of the object’s composition. Field-portable systems, such as Idaho National Laboratory’s PINS system, have used standard liquid-nitrogen-cooled high-purity germanium (HPGe) detectors to perform this function. These detectors have performed very well in the past, but the requirement of liquid-nitrogen cooling limits their use to areas where liquid nitrogen is readily available or produced on-site. Also, having a relatively large volume of liquid nitrogen close to the detector can impact some assessments, possibly leading to a false detection of explosives or other nitrogen-containing chemical. Use of a mechanically-cooled HPGe detector is therefore very attractive for PGNAA applications where nitrogen detection is critical or where liquid-nitrogen logistics are problematic. Mechanically-cooled HPGe detectors constructed from p-type germanium, such as Ortec’s trans-SPEC, have been commercially available for several years. In order to assess whether these detectors would be suitable for use in a fielded PGNAA system, Idaho National Laboratory (INL) has been performing a number of tests of the resistance of mechanically-cooled HPGe detectors to neutron damage. These detectors have been standard commercially-available p-type HPGe detectors as well as prototype n-type HPGe detectors. These tests compare the performance of these different detector types as a function of crystal temperature and incident neutron fluence on the crystal.

  11. A Search of Neutrino Magnetic Moments with a High-Purity Germanium Detector at the Kuo-Sheng Nuclear Power Station

    E-Print Network [OSTI]

    Wong, H T; Lin, S T; Lee, F S; Singh, V; Wu, S C; Chang, C Y; Chang, H M; Chen, C P; Chou, M H; Deniz, M; Fang, J M; Hu, C H; Huang, H X; Jon, G C; Kuo, W S; Lai, W P; Lee, S C; Li, J; Liao, H Y; Lin, F K; Lin, S K; Lu, J Q; Sheng, H Y; Su, R F; Tong, W S; Xin, B; Yeh, T R; Yue, Q; Zhou, Z Y; Zhuang, B A

    2007-01-01

    A search of neutrino magnetic moments was carried out at the Kuo-Sheng Nuclear Power Station at a distance of 28 m from the 2.9 GW reactor core. With a high purity germanium detector of mass 1.06 kg surrounded by scintillating NaI(Tl and CsI(Tl) crystals as anti-Compton detectors, a detection threshold of 5 keV and a background level of 1 $\\cpd$ near threshold were achieved. Details of the reactor neutrino source, experimental hardware, background understanding and analysis methods are presented. Based on 570.7 and 127.8 days of Reactor ON and OFF data, respectively, at an average Reactor ON electron anti-neutrino flux of $\\rm{6.44 \\times 10^{12} cm^{-2} s^{-1}}$, the limit on the neutrino magnetic moments of $\\rm{\\munuebar < 7.2 \\times 10^{-11} \\mub}$ at 90% confidence level was derived. Indirect bounds of the $\

  12. Ultra High-Rate Germanium (UHRGe) Modeling Status Report

    SciTech Connect (OSTI)

    Warren, Glen A.; Rodriguez, Douglas C.

    2012-06-07

    The Ultra-High Rate Germanium (UHRGe) project at Pacific Northwest National Laboratory (PNNL) is conducting research to develop a high-purity germanium (HPGe) detector that can provide both the high resolution typical of germanium and high signal throughput. Such detectors may be beneficial for a variety of potential applications ranging from safeguards measurements of used fuel to material detection and verification using active interrogation techniques. This report describes some of the initial radiation transport modeling efforts that have been conducted to help guide the design of the detector as well as a description of the process used to generate the source spectrum for the used fuel application evaluation.

  13. Global High-purity Pentoxide Industry 2015 Market Research Report...

    Open Energy Info (EERE)

    Global High-purity Pentoxide Industry 2015 Market Research Report Home Gosreports's picture Submitted by Gosreports(70) Contributor 2 July, 2015 - 21:10 Global High-purity...

  14. Method of high purity silane preparation

    DOE Patents [OSTI]

    Tsuo, Y. Simon (Golden, CO); Belov, Eugene P. (Moscow, RU); Gerlivanov, Vadim G. (Moscow, RU); Zadde, Vitali V. (Moscow, RU); Kleschevnikova, Solomonida I. (Moscow, RU); Korneev, Nikolai N. (Moscow, RU); Lebedev, Eugene N. (Moscow, RU); Pinov, Akhsarbek B. (Moscow, RU); Ryabenko, Eugene A. (Moscow, RU); Strebkov, Dmitry S. (Moscow, RU); Chernyshev, Eugene A. (Moscow, RU)

    2000-01-01

    A process for the preparation of high purity silane, suitable for forming thin layer silicon structures in various semiconductor devices and high purity poly- and single crystal silicon for a variety of applications, is provided. Synthesis of high-purity silane starts with a temperature assisted reaction of metallurgical silicon with alcohol in the presence of a catalyst. Alcoxysilanes formed in the silicon-alcohol reaction are separated from other products and purified. Simultaneous reduction and oxidation of alcoxysilanes produces gaseous silane and liquid secondary products, including, active part of a catalyst, tetra-alcoxysilanes, and impurity compounds having silicon-hydrogen bonds. Silane is purified by an impurity adsorption technique. Unreacted alcohol is extracted and returned to the reaction with silicon. Concentrated mixture of alcoxysilanes undergoes simultaneous oxidation and reduction in the presence of a catalyst at the temperature -20.degree. C. to +40.degree. C. during 1 to 50 hours. Tetra-alcoxysilane extracted from liquid products of simultaneous oxidation and reduction reaction is directed to a complete hydrolysis. Complete hydrolysis of tetra-alcoxysilane results in formation of industrial silica sol and alcohol. Alcohol is dehydrated by tetra-alcoxysilane and returned to the reaction with silicon.

  15. PhosPlusPhosPlus High-Purity

    E-Print Network [OSTI]

    Kaiser, Todd J.

    depositions. · The use of high-purity raw materials results in high-purity doping of single crystalPlus sources are manufactured from raw materials exhibiting very high purity. These materials are made using represent a significant advancement in the field of phosphorus dopant materials. Their ability to easily

  16. GIOVE - A New Detector Setup for High Sensitivity Germanium Spectroscopy At Shallow Depth

    E-Print Network [OSTI]

    Gerd Heusser; Marc Weber; Janina Hakenmüller; Matthias Laubenstein; Manfred Lindner; Werner Maneschg; Hardy Simgen; Dominik Stolzenburg; Herbert Strecker

    2015-07-13

    We report on the development and construction of the high-purity germanium spectrometer setup GIOVE (Germanium Inner Outer Veto), recently built and now operated at the shallow underground laboratory of the Max-Planck-Institut f\\"ur Kernphysik, Heidelberg. Particular attention was paid to the design of a novel passive and active shield, aiming at efficient rejection of environmental and muon induced radiation backgrounds. The achieved sensitivity level of <100 {\\mu}Bq/kg for primordial radionuclides from U and Th in typical {\\gamma} ray sample screening measurements is unique among instruments located at comparably shallow depths and can compete with instruments at far deeper underground sites.

  17. HYDROGEN CONCENTRATION AND DISTRIBUTION IN HIGH-PURITY GERMANIUM CRYSTALS

    E-Print Network [OSTI]

    Hansen, W.L.

    2010-01-01

    melting point. By analogy, hydrogen permeation measurementsin silicon suggest that the hydrogen solubility also is notNo. 1, February 1982 HYDROGEN CONCENTRATION AND DISTRIBUTION

  18. Crystal growth and detector performance of large size high-purity Ge crystals

    E-Print Network [OSTI]

    Wang, Guojian; Mei, Hao; Mei, Dongming; Irmscher, Klaus; Guan, Yutong; Yang, Gang

    2015-01-01

    High-purity germanium crystals approximately 12 cm in diameter were grown in a hydrogen atmosphere using the Czochralski method. The dislocation density of the crystals was determined to be in the range of 2000 - 4200 cm-2, which meets a requirement for use as a radiation detector. The axial and radial distributions of impurities in the crystals were measured and are discussed. A planar detector was also fabricated from one of the crystals and then evaluated for electrical and spectral performance. Measurements of gamma-ray spectra from Cs-137 and Am-241 sources demonstrate that the detector has excellent energy resolution.

  19. Crystal growth and detector performance of large size high-purity Ge crystals

    E-Print Network [OSTI]

    Guojian Wang; Mark Amman; Hao Mei; Dongming Mei; Klaus Irmscher; Yutong Guan; Gang Yang

    2015-05-07

    High-purity germanium crystals approximately 12 cm in diameter were grown in a hydrogen atmosphere using the Czochralski method. The dislocation density of the crystals was determined to be in the range of 2000 - 4200 cm-2, which meets a requirement for use as a radiation detector. The axial and radial distributions of impurities in the crystals were measured and are discussed. A planar detector was also fabricated from one of the crystals and then evaluated for electrical and spectral performance. Measurements of gamma-ray spectra from Cs-137 and Am-241 sources demonstrate that the detector has excellent energy resolution.

  20. Production of High Purity Niobium Ingots at CBMM

    SciTech Connect (OSTI)

    Moura, Lourenco de; Faria Sousa, Clovis Antonio de; Burgos Cruz, Edmundo [CBMM-Companhia Brasileira de Metalurgia e Mineracao, Fazenda Corrego da Mata, P.O. Box 838.183.903, Araxa, MG (Brazil)

    2011-03-31

    CBMM is a fully integrated company, from the mine to the end line of the production chain, supplying different niobium products to the world market: ferroniobium, nickelniobium, niobium pentoxide and high purity metallic niobium. This high purity metallic niobium has long been known to exhibit superconductivity below 9.25 Kelvin. This characteristic has the potential to bring technological benefits for many different areas such as medicine, computing and environment. This paper presents the raw material requirements as well as CBMM experience on producing high purity niobium ingots. The results prove that CBMM material can be the best solution for special applications such as low cost superconductive radiofrequency cavities.

  1. Determination of carbon, nitrogen, and oxygen in high purity magnesium 

    E-Print Network [OSTI]

    Roche, Neil Gerard

    1981-01-01

    DETERMINATION OF CARBON, NITROGEN, AND OXYGEN IN HIGH PURITY MAGNESIUM A Thesis by NEIL GERARD ROCHE Submitted to the Graduate College of Texas A8cM University in partial i'ulfillment of the requirement for the degree of MASTER OF SCIENCE... December 1981 Major Subject: Chemistry DETERMINATION OF CARBON, NITROGEN, AND OXYGEN IN HIGH PURITY MAGNESIUM A Thesis by NEIL GERARD ROCHE Approved as to style and content by: E. A. Schweikert (Chairman of Committee) G. J. Bastiaans (Member) L...

  2. Low cost routes to high purity silicon and derivatives thereof

    DOE Patents [OSTI]

    Laine, Richard M; Krug, David James; Marchal, Julien Claudius; Mccolm, Andrew Stewart

    2013-07-02

    The present invention is directed to a method for providing an agricultural waste product having amorphous silica, carbon, and impurities; extracting from the agricultural waste product an amount of the impurities; changing the ratio of carbon to silica; and reducing the silica to a high purity silicon (e.g., to photovoltaic silicon).

  3. Germanium-76 Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Engelhard, Mark H.; Zhu, Zihua

    2011-04-01

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). The DEMONSTRATOR will utilize 76Ge from Russia, and the first one gram sample was received from the supplier for analysis on April 24, 2011. The Environmental Molecular Sciences facility, a DOE user facility at PNNL, was used to make the required isotopic and chemical purity measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR. The results of this first analysis are reported here.

  4. Method and apparatus for producing high purity silicon

    DOE Patents [OSTI]

    Olson, J.M.

    1983-05-27

    A method for producing high purity silicon includes forming a copper silicide alloy and positioning the alloy within an enclosure. A filament member is also placed within the enclosure opposite the alloy. The enclosure is then filled with a chemical vapor transport gas adapted for transporting silicon. Finally, both the filament member and the alloy are heated to temperatures sufficient to cause the gas to react with silicon at the alloy surface and deposit the reacted silicon on the filament member. In addition, an apparatus for carrying out this method is also disclosed.

  5. Method and apparatus for producing high purity silicon

    DOE Patents [OSTI]

    Olson, Jerry M. (Lakewood, CO)

    1984-01-01

    A method for producing high purity silicon includes forming a copper silie alloy and positioning the alloy within an enclosure. A filament member is also placed within the enclosure opposite the alloy. The enclosure is then filled with a chemical vapor transport gas adapted for transporting silicon. Finally, both the filament member and the alloy are heated to temperatures sufficient to cause the gas to react with silicon at the alloy surface and deposit the reacted silicon on the filament member. In addition, an apparatus for carrying out this method is also disclosed.

  6. Observing bulk diamond spin coherence in high-purity nanodiamonds

    E-Print Network [OSTI]

    Helena S. Knowles; Dhiren M. Kara; Mete Atature

    2013-10-03

    Nitrogen-vacancy centres (NVs) in diamond are attractive for research straddling quantum information science and nanoscale magnetometry and thermometry. While ultrapure bulk diamond NVs sustain the longest spin coherence times among optically accessible spins, nanodiamond NVs display persistently poor spin coherence. Here we introduce high-purity nanodiamonds accommodating record-long NV coherence times, >60 us, observed via universal dynamical decoupling. We show that the main contribution to decoherence comes from nearby nitrogen impurities rather than surface states. We protect the NV spin free precession, essential to DC magnetometry, by driving solely these impurities into the motional narrowing regime. This extends the NV free induction decay time from 440 ns, longer than that in type Ib bulk diamond, to 1.27 us, which is comparable to that in type IIa (impurity-free) diamond. These properties allow the simultaneous exploitation of both high sensitivity and nanometre resolution in diamond-based emergent quantum technologies.

  7. MAJORANA Collaboration's experience with germanium detectors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mertens, S.; Abgrall, N.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; et al

    2015-05-01

    The goal of the Majorana Demonstrator project is to search for 0??? decay in 76Ge. Of all candidate isotopes for 0???, 76Ge has some of the most favorable characteristics. Germanium detectors are a well established technology, and in searches for 0???, the high purity germanium crystal acts simultaneously as source and detector. Furthermore, p-type germanium detectors provide excellent energy resolution and a specially designed point contact geometry allows for sensitive pulse shape discrimination. This paper will summarize the experiences the MAJORANA collaboration made with enriched germanium detectors manufactured by ORTEC®®. The process from production, to characterization and integration in MAJORANAmore »mounting structure will be described. A summary of the performance of all enriched germanium detectors will be given.« less

  8. Electric characteristics of germanium Vertical Multijunction (VMJ) photovoltaic cells under high intensity illumination

    SciTech Connect (OSTI)

    Unishkov, V.A.

    1997-03-01

    This paper presents the results of the performance evaluation of Vertical Multijunction (VMJ) germanium (Ge) photovoltaic (PV) cells. Vertical Multijunction Germanium Photovoltaic cells offer several advantages for Thermophotovoltaic (TPV) applications such as high intensity light conversion, low series resistance, more efficient coupling to lower temperature sources, high output voltage, simplified heat rejection system as well as potentially simple fabrication technology and low cost photovoltaic converter device. {copyright} {ital 1997 American Institute of Physics.}

  9. Generation of high-purity higher-order Laguerre-Gauss beams at high laser power

    E-Print Network [OSTI]

    L. Carbone; C. Bogan; P. Fulda; A. Freise; B. Willke

    2013-03-14

    We have investigated the generation of highly pure higher-order Laguerre-Gauss (LG) beams at high laser power of order 100W, the same regime that will be used by 2nd generation gravitational wave interferometers such as Advanced LIGO. We report on the generation of a helical type LG33 mode with a purity of order 97% at a power of 83W, the highest power ever reported in literature for a higher-order LG mode.

  10. High-efficiency spectral purity filter for EUV lithography

    DOE Patents [OSTI]

    Chapman, Henry N. (Livermore, CA)

    2006-05-23

    An asymmetric-cut multilayer diffracts EUV light. A multilayer cut at an angle has the same properties as a blazed grating, and has been demonstrated to have near-perfect performance. Instead of having to nano-fabricate a grating structure with imperfections no greater than several tens of nanometers, a thick multilayer is grown on a substrate and then cut at an inclined angle using coarse and inexpensive methods. Effective grating periods can be produced this way that are 10 to 100 times smaller than those produced today, and the diffraction efficiency of these asymmetric multilayers is higher than conventional gratings. Besides their ease of manufacture, the use of an asymmetric multilayer as a spectral purity filter does not require that the design of an EUV optical system be modified in any way, unlike the proposed use of blazed gratings for such systems.

  11. High Purity Germanium Detectors at LBNL | U.S. DOE Office of...

    Office of Science (SC) Website

    Contact Information Nuclear Physics U.S. Department of Energy SC-26Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833...

  12. Active noise canceling system for mechanically cooled germanium radiation detectors

    DOE Patents [OSTI]

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

  13. Large Cryogenic Germanium Detector. Final Report

    SciTech Connect (OSTI)

    Mandic, Vuk

    2013-02-13

    The goal of this project was to investigate possible ways of increasing the size of cryogenic Ge detectors. This project identified two possible approaches to increasing the individual cryogenic Ge detector size. The first approach relies on using the existing technology for growing detector-grade (high-purity) germanium crystals of dislocation density 100-7000 cm{sup -2}. The second approach is to consider dislocation-free Ge crystals.

  14. Top-Down, Scalable Fabrication of High Purity Fluorescent Nanodiamonds

    E-Print Network [OSTI]

    Li, Luozhou

    We demonstrate a fabrication technique for high volume production of high quality nanocrystals from bulk chemical vapor deposition diamond. Ramsey and Spin-Echo measurements confirm the long spin coherence of nitrogen ...

  15. Catalytic CVD generation of high-purity single-walled carbon nanotubes at low temperature

    E-Print Network [OSTI]

    Maruyama, Shigeo

    CVD Catalytic CVD generation of high-purity single-walled carbon nanotubes at low temperature-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 We have demonstrated the high-quality and low-temperature generation on the generation temperature and gas flow rate. In order to create nanotube devices, we tried to generate SWNTs

  16. Signal modeling of high-purity Ge detectors with a small read-out electrode and application to neutrinoless double beta decay search in Ge-76

    E-Print Network [OSTI]

    M. Agostini; C. A. Ur; D. Budjáš; E. Bellotti; R. Brugnera; C. M. Cattadori; A. di Vacri; A. Garfagnini; L. Pandola; S. Schönert

    2011-01-17

    The GERDA experiment searches for the neutrinoless double beta decay of Ge-76 using high-purity germanium detectors enriched in Ge-76. The analysis of the signal time structure provides a powerful tool to identify neutrinoless double beta decay events and to discriminate them from gamma-ray induced backgrounds. Enhanced pulse shape discrimination capabilities of "Broad Energy Germanium" detectors with a small read-out electrode have been recently reported. This paper describes the full simulation of the response of such a detector, including the Monte Carlo modeling of radiation interaction and subsequent signal shape calculation. A pulse shape discrimination method based on the ratio between the maximum current signal amplitude and the event energy applied to the simulated data shows quantitative agreement with the experimental data acquired with calibration sources. The simulation has been used to study the survival probabilities of the decays which occur inside the detector volume and are difficult to assess experimentally. Such internal decay events are produced by the cosmogenic radio-isotopes Ge-68 and Co-60 and the neutrinoless double beta decay of Ge-76. Fixing the experimental acceptance of the double escape peak of the 2.614 MeV photon to 90%, the estimated survival probabilities at Qbb = 2.039 MeV are (86+-3)% for Ge-76 neutrinoless double beta decays, (4.5+-0.3)% for the Ge-68 daughter Ga-68, and (0.9+0.4-0.2)% for Co-60 decays.

  17. Low-temperature germanium ultra-high vacuum chemical vapor deposition for back-end photonic integration

    E-Print Network [OSTI]

    Kimerling, Lionel C.

    Polycrystalline germanium (poly-Ge) grown on amorphous Si (a-Si) by ultra-high vacuum chemical vapor deposition (UHVCVD) over oxide barriers at low temperatures (Tles450degC) exhibits a larger grain size and lower defect ...

  18. Comparison of Deformation in High-Purity Single/Large Grain and Polycrystalline Niobium Superconducting Cavities

    SciTech Connect (OSTI)

    Ganapati Rao Myneni; Peter Kneisel

    2005-07-10

    The current approach for the fabrication of superconducting radio frequency (SRF) cavities is to roll and deep draw sheets of polycrystalline high-purity niobium. Recently, a new technique was developed at Jefferson Laboratory that enables the fabrication of single-crystal high-purity Nb SRF cavities. To better understand the differences between SRF cavities fabricated out of fine-grained polycrystalline sheet in the standard manner and single crystal cavities fabricated by the new technique, two half-cells were produced according to the two different procedures and compared using a variety of analytical techniques including optical microscopy, scanning laser confocal microscopy, profilometry, and X-ray diffraction. Crystallographic orientations, texture, and residual stresses were determined in the samples before and after forming and this poster presents the results of this ongoing study.

  19. High Purity Americium-241 for Fuel Cycle R&D Program

    SciTech Connect (OSTI)

    Dr. Paul A. Lessing

    2011-07-01

    Previously the U.S. Department of Energy released Am-241 for various applications such as smoke detectors and Am-Be neutron sources for oil wells. At this date there is a shortage of usable, higher purity Am-241 in metal and oxide form available in the United States. Recently, the limited source of Am-241 has been from Russia with production being contracted to existing customers. The shortage has resulted in the price per gram rising dramatically over the last few years. DOE-NE currently has need for high purity Am-241 metal and oxide to fabricate fuel pellets for reactor testing in the Fuel Cycle R&D program. All the available high purity americium has been gathered from within the DOE system of laboratories. However, this is only a fraction of the projected needs of FCRD over the next 10 years. Therefore, FCR&D has proposed extraction and purification concepts to extract Am-241 from a mixed AmO2-PuO2 feedstock stored at the Savannah River Site. The most simple extraction system is based upon high temperature reduction using lanthanum metal with concurrent evaporation and condensation to produce high purity Am metal. Metallic americium has over a four order of magnitude higher vapor pressure than plutonium. Results from small-scale reduction experiments are presented. These results confirm thermodynamic predictions that at 1000 deg C metallic lanthanum reduces both PuO2 and AmO2. Faster kinetics are expected for temperatures up to about 1500 deg C.

  20. Germanium-76 Sample Analysis: Revision 3

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Zhu, Zihua; Engelhard, Mark H.

    2011-09-19

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0{nu}{beta}{beta}). The DEMONSTRATOR will utilize 76Ge from Russia. The first one-gram sample was received from the supplier for analysis on April 24, 2011. The second one-gram sample was received from the supplier for analysis on July 12, 2011. The third sample, which came from the first large shipment of germanium from the vendor, was received from Oak Ridge National Laboratory (ORNL) on September 13, 2011. The Environmental Molecular Sciences facility, a DOE user facility at PNNL, was used to make the required isotopic and chemical purity measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR. The results of these analyses are reported here. The isotopic composition of a sample of natural germanium was also measured twice. Differences in the result between these two measurements led to a re-measurement of the second 76Ge sample.

  1. Electrical and mechanical studies of high purity aluminum single crystals at 4.2 K under cyclic strain 

    E-Print Network [OSTI]

    Zou, Hong

    1995-01-01

    The objective of this research is to investigate the effects of orientation on strain hardening and resistivity degradation in high purity aluminum single crystals resulting from uniaxial cyclic strain at 4.2 K. Aluminum crystals with various...

  2. Process for producing high purity silicon nitride by the direct reaction between elemental silicon and nitrogen-hydrogen liquid reactants

    DOE Patents [OSTI]

    Pugar, Eloise A. (Isla Vista, CA); Morgan, Peter E. D. (Thousand Oaks, CA)

    1990-01-01

    A process is disclosed for producing, at a low temperature, a high purity reaction product consisting essentially of silicon, nitrogen, and hydrogen which can then be heated to produce a high purity alpha silicon nitride. The process comprises: reacting together a particulate elemental high purity silicon with a high purity nitrogen-hydrogen reactant in its liquid state (such as ammonia or hydrazine) having the formula: N.sub.n H.sub.(n+m) wherein: n=1-4 and m=2 when the nitrogen-hydrogen reactant is straight chain, and 0 when the nitrogen-hydrogen reactant is cyclic. High purity silicon nitride can be formed from this intermediate product by heating the intermediate product at a temperature of from about 1200.degree.-1700.degree. C. for a period from about 15 minutes up to about 2 hours to form a high purity alpha silicon nitride product. The discovery of the existence of a soluble Si-N-H intermediate enables chemical pathways to be explored previously unavailable in conventional solid state approaches to silicon-nitrogen ceramics.

  3. Process for producing high purity silicon nitride by the direct reaction between elemental silicon and nitrogen-hydrogen liquid reactants

    DOE Patents [OSTI]

    Pugar, E.A.; Morgan, P.E.D.

    1987-09-15

    A process is disclosed for producing, at a low temperature, a high purity reaction product consisting essentially of silicon, nitrogen, and hydrogen which can then be heated to produce a high purity alpha silicon nitride. The process comprises: reacting together a particulate elemental high purity silicon with a high purity nitrogen-hydrogen reactant in its liquid state (such as ammonia or hydrazine) having the formula: N/sub n/H/sub (n+m)/ wherein: n = 1--4 and m = 2 when the nitrogen-hydrogen reactant is straight chain, and 0 when the nitrogen-hydrogen reactant is cyclic. High purity silicon nitride can be formed from this intermediate product by heating the intermediate product at a temperature of from about 1200--1700/degree/C for a period from about 15 minutes up to about 2 hours to form a high purity alpha silicon nitride product. The discovery of the existence of a soluble Si/endash/N/endash/H intermediate enables chemical pathways to be explored previously unavailable in conventional solid-state approaches to silicon-nitrogen ceramics

  4. New red phosphor for near-ultraviolet light-emitting diodes with high color-purity

    SciTech Connect (OSTI)

    Wang, Zhengliang; He, Pei; Wang, Rui; Zhao, Jishou; Gong, Menglian

    2010-02-15

    New red phosphors, Na{sub 5}Eu(MoO{sub 4}){sub 4} doped with boron oxide were prepared by the solid-state reaction. Their structure and photo-luminescent properties were investigated. With the introduction of boron oxide, the red emission intensity of the phosphors under 395 nm excitation is strengthened, with high color-purity (x = 0.673, y = 0.327). The single red light-emitting diode was obtained by combining InGaN chip with the red phosphor, bright red light can be observed by naked eyes from the red light-emitting diodes under a forward bias of 20 mA.

  5. SIMULTANEOUS PRODUCTION OF HIGH-PURITY HYDROGEN AND SEQUESTRATION-READY CO2 FROM SYNGAS

    SciTech Connect (OSTI)

    Linda Denton; Hana Lorethova; Tomasz Wiltowski; Court Moorefield; Parag Kulkarni; Vladimir Zamansky; Ravi Kumar

    2003-12-01

    This final report summarizes the progress made on the program ''Simultaneous Production of High-Purity Hydrogen and Sequestration-Ready CO{sub 2} from Syngas (contract number DE-FG26-99FT40682)'', during October 2000 through September of 2003. GE Energy and Environmental Research (GE-EER) and Southern Illinois University (SIU) at Carbondale conducted the research work for this program. This program addresses improved methods to efficiently produce simultaneous streams of high-purity hydrogen and separated carbon dioxide from synthesis gas (syngas). The syngas may be produced through either gasification of coal or reforming of natural gas. The process of production of H{sub 2} and separated CO{sub 2} utilizes a dual-bed reactor and regenerator system. The reactor produces hydrogen and the regenerator produces separated CO{sub 2}. The dual-bed system can be operated under either a circulating fluidized-bed configuration or a cyclic fixed-bed configuration. Both configurations were evaluated in this project. The experimental effort was divided into lab-scale work at SIU and bench-scale work at GE-EER. Tests in a lab-scale fluidized bed system demonstrated the process for the conversion of syngas to high purity H{sub 2} and separated CO{sub 2}. The lab-scale system generated up to 95% H{sub 2} (on a dry basis). Extensive thermodynamic analysis of chemical reactions between the syngas and the fluidized solids determined an optimum range of temperature and pressure operation, where the extent of the undesirable reactions is minimum. The cycling of the process between hydrogen generation and oxygen regeneration has been demonstrated. The fluidized solids did not regenerate completely and the hydrogen purity in the reuse cycle dropped to 70% from 95% (on a dry basis). Changes in morphology and particle size may be the most dominant factor affecting the efficiency of the repeated cycling between hydrogen production and oxygen regeneration. The concept of simultaneous production of hydrogen and separated stream of CO{sub 2} was proved using a fixed bed 2 reactor system at GE-EER. This bench-scale cyclic fixed-bed reactor system designed to reform natural gas to syngas has been fabricated in another coordinated DOE project. This system was modified to reform natural gas to syngas and then convert syngas to H{sub 2} and separated CO{sub 2}. The system produced 85% hydrogen (dry basis).

  6. Simulations for Tracking Cosmogenic Activation in Germanium and Copper

    SciTech Connect (OSTI)

    Aguayo, Estanislao; Kouzes, Richard T.; Orrell, John L.

    2011-11-01

    High-purity germanium (HPGe) detectors housed in copper cryostats and shielding materials are used in measurements of the extraordinarily rare nuclear decay process, neutrinoless double-beta decay (0???), and for dark matter searches. Cosmogenic production of 68Ge and 60Co in the germanium and copper represent an irreducible background to these experiments as the subsequent decays of these isotopes can mimic the signals of interest. These radioactive isotopes can be removed by chemical and/or isotopic separation, but begin to grow-in to the material after separation until the material is moved deep underground. This work is motivated by the need to have a reliable, experimentally benchmarked simulation tool for evaluating shielding materials used during transportation and near-surface manufacturing of experiment components. The resulting simulations tool has been used to enhance the effectiveness of an existing transport shield used to ship enriched germanium from the separations facility to the detector manufacturing facility.

  7. Production of carbon monoxide-free hydrogen and helium from a high-purity source

    DOE Patents [OSTI]

    Golden, Timothy Christopher (Allentown, PA); Farris, Thomas Stephen (Bethlehem, PA)

    2008-11-18

    The invention provides vacuum swing adsorption processes that produce an essentially carbon monoxide-free hydrogen or helium gas stream from, respectively, a high-purity (e.g., pipeline grade) hydrogen or helium gas stream using one or two adsorber beds. By using physical adsorbents with high heats of nitrogen adsorption, intermediate heats of carbon monoxide adsorption, and low heats of hydrogen and helium adsorption, and by using vacuum purging and high feed stream pressures (e.g., pressures of as high as around 1,000 bar), pipeline grade hydrogen or helium can purified to produce essentially carbon monoxide -free hydrogen and helium, or carbon monoxide, nitrogen, and methane-free hydrogen and helium.

  8. Surface preparation for high purity alumina ceramics enabling direct brazing in hydrogen atmospheres

    DOE Patents [OSTI]

    Cadden, Charles H. (Danville, CA); Yang, Nancy Yuan Chi (Lafayette, CA); Hosking, Floyd M. (Albuquerque, NM)

    2001-01-01

    The present invention relates to a method for preparing the surface of a high purity alumina ceramic or sapphire specimen that enables direct brazing in a hydrogen atmosphere using an active braze alloy. The present invention also relates to a method for directly brazing a high purity alumina ceramic or sapphire specimen to a ceramic or metal member using this method of surface preparation, and to articles produced by this brazing method. The presence of silicon, in the form of a SiO.sub.2 -containing surface layer, can more than double the tensile bond strength in alumina ceramic joints brazed in a hydrogen atmosphere using an active Au-16Ni-0.75 Mo-1.75V filler metal. A thin silicon coating applied by PVD processing can, after air firing, produce a semi-continuous coverage of the alumina surface with a SiO.sub.2 film. Room temperature tensile strength was found to be proportional to the fraction of air fired surface covered by silicon-containing films. Similarly, the ratio of substrate fracture versus interface separation was also related to the amount of surface silicon present prior to brazing. This process can replace the need to perform a "moly-manganese" metallization step.

  9. First 10 kg of Naked Germanium Detectors in Liquid Nitrogen installed in the GENIUS-Test-Facility

    E-Print Network [OSTI]

    H. V. Klapdor-Kleingrothaus; O. Chkvorez; I. V. Krivosheina; H. Strecker; C. Tomei

    2003-09-15

    The first four naked high purity Germanium detectors were installed successfully in liquid nitrogen in the GENIUS-Test-Facility (GENIUS-TF) in the GRAN SASSO Underground Laboratory on May 5, 2003. This is the first time ever that this novel technique aiming at extreme background reduction in search for rare decays is going to be tested underground. First operational parameters are presented.

  10. HIGH EFFICIENCY AMORPHOUS SILICON GERMANIUM SOLAR CELLS X. Liao, W. Du, X. Yang, H. Povolny, X. Xiang and X. Deng

    E-Print Network [OSTI]

    Deng, Xunming

    -SiGe) alloy has been widely used as narrow bandgap i-layers in multi-junction a-Si based solar cells [1, 2HIGH EFFICIENCY AMORPHOUS SILICON GERMANIUM SOLAR CELLS X. Liao, W. Du, X. Yang, H. Povolny, X ABSTRACT We report high-efficiency single-junction a-SiGe n-i-p solar cells deposited using rf PECVD

  11. High-purity hydrogen gas from the reaction between BOF steel slag and water in the 473e673 K

    E-Print Network [OSTI]

    Montes-Hernandez, German

    energy (above 120 MJ/kg); 2) water is the main by-product in hydrogen fuel cell or during combustion carbonated beforehand at 0.142 Æ 0.002 kg of CO2 per kg of slag. The reaction was found to be thermally activated. A high purity hydrogen (99.995%) is produced with non-carbonated steel slag below 573 K whereas

  12. Germanium detectors in homeland security at PNNL

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stave, S.

    2015-05-01

    Neutron and gamma-ray detection is used for non-proliferation and national security applications. While lower energy resolution detectors such as NaI(Tl) have their place, high purity germanium (HPGe) also has a role to play. A detection with HPGe is often a characterization due to the very high energy resolution. However, HPGe crystals remain small and expensive leaving arrays of smaller crystals as an excellent solution. PNNL has developed two similar HPGe arrays for two very different applications. One array, the Multisensor Aerial Radiation Survey (MARS) detector is a fieldable array that has been tested on trucks, boats, and helicopters. The CASCADESmore »HPGe array is an array designed to assay samples in a low background environment. The history of HPGe arrays at PNNL and the development of MARS and CASCADES will be detailed in this paper along with some of the other applications of HPGe at PNNL.« less

  13. Phonon Quasidiffusion in Cryogenic Dark Matter Search Large Germanium Detectors

    SciTech Connect (OSTI)

    Leman, S.W.; /MIT, MKI; Cabrera, B.; /Stanford U., Phys. Dept.; McCarthy, K.A.; /MIT, MKI; Pyle, M.; /Stanford U., Phys. Dept.; Resch, R.; /SLAC; Sadoulet, B.; Sundqvist, K.M.; /LBL, Berkeley; Brink, P.L.; Cherry, M.; /Stanford U., Phys. Dept.; Do Couto E Silva, E.; /SLAC; Figueroa-Feliciano, E.; /MIT, MKI; Mirabolfathi, N.; Serfass, B.; /UC, Berkeley; Tomada, A.; /Stanford U., Phys. Dept.

    2012-06-04

    We present results on quasidiffusion studies in large, 3 inch diameter, 1 inch thick [100] high purity germanium crystals, cooled to 50 mK in the vacuum of a dilution refrigerator, and exposed with 59.5 keV gamma-rays from an Am-241 calibration source. We compare data obtained in two different detector types, with different phonon sensor area coverage, with results from a Monte Carlo. The Monte Carlo includes phonon quasidiffusion and the generation of phonons created by charge carriers as they are drifted across the detector by ionization readout channels.

  14. High Purity Hydrogen Production with In-Situ Carbon Dioxide and Sulfur Capture in a Single Stage Reactor

    SciTech Connect (OSTI)

    Nihar Phalak; Shwetha Ramkumar; Daniel Connell; Zhenchao Sun; Fu-Chen Yu; Niranjani Deshpande; Robert Statnick; Liang-Shih Fan

    2011-07-31

    Enhancement in the production of high purity hydrogen (H{sub 2}) from fuel gas, obtained from coal gasification, is limited by thermodynamics of the water gas shift (WGS) reaction. However, this constraint can be overcome by conducting the WGS in the presence of a CO{sub 2}-acceptor. The continuous removal of CO{sub 2} from the reaction mixture helps to drive the equilibrium-limited WGS reaction forward. Since calcium oxide (CaO) exhibits high CO{sub 2} capture capacity as compared to other sorbents, it is an ideal candidate for such a technique. The Calcium Looping Process (CLP) developed at The Ohio State University (OSU) utilizes the above concept to enable high purity H{sub 2} production from synthesis gas (syngas) derived from coal gasification. The CLP integrates the WGS reaction with insitu CO{sub 2}, sulfur and halide removal at high temperatures while eliminating the need for a WGS catalyst, thus reducing the overall footprint of the hydrogen production process. The CLP comprises three reactors - the carbonator, where the thermodynamic constraint of the WGS reaction is overcome by the constant removal of CO{sub 2} product and high purity H{sub 2} is produced with contaminant removal; the calciner, where the calcium sorbent is regenerated and a sequestration-ready CO{sub 2} stream is produced; and the hydrator, where the calcined sorbent is reactivated to improve its recyclability. As a part of this project, the CLP was extensively investigated by performing experiments at lab-, bench- and subpilot-scale setups. A comprehensive techno-economic analysis was also conducted to determine the feasibility of the CLP at commercial scale. This report provides a detailed account of all the results obtained during the project period.

  15. Preparation of uniform nanoparticles of ultra-high purity metal oxides, mixed metal oxides, metals, and metal alloys

    DOE Patents [OSTI]

    Woodfield, Brian F.; Liu, Shengfeng; Boerio-Goates, Juliana; Liu, Qingyuan; Smith, Stacey Janel

    2012-07-03

    In preferred embodiments, metal nanoparticles, mixed-metal (alloy) nanoparticles, metal oxide nanoparticles and mixed-metal oxide nanoparticles are provided. According to embodiments, the nanoparticles may possess narrow size distributions and high purities. In certain preferred embodiments, methods of preparing metal nanoparticles, mixed-metal nanoparticles, metal oxide nanoparticles and mixed-metal nanoparticles are provided. These methods may provide tight control of particle size, size distribution, and oxidation state. Other preferred embodiments relate to a precursor material that may be used to form nanoparticles. In addition, products prepared from such nanoparticles are disclosed.

  16. High-capacity nanostructured germanium-containing materials and lithium alloys thereof

    DOE Patents [OSTI]

    Graetz, Jason A. (Upton, NY); Fultz, Brent T. (Pasadena, CA); Ahn, Channing (Pasadena, CA); Yazami, Rachid (Los Angeles, CA)

    2010-08-24

    Electrodes comprising an alkali metal, for example, lithium, alloyed with nanostructured materials of formula Si.sub.zGe.sub.(z-1), where 0germanium exhibit a combination of improved capacities, cycle lives, and/or cycling rates compared with similar electrodes made from graphite. These electrodes are useful as anodes for secondary electrochemical cells, for example, batteries and electrochemical supercapacitors.

  17. RADIATION DAMAGE OF GERMANIUM DETECTORS

    E-Print Network [OSTI]

    Pehl, Richard H.

    2011-01-01

    the high-energy proton damage than was the planar detector.as far as radiation damage is concerned. Unfortunately, some28-29, 1978 LBL-7967 RADIATION DAMAGE OF GERMANIUM DETECTORS

  18. Technology for processing ammonium rhodanide of coking plants into high-purity ammonium thiocyanate and thiourea

    SciTech Connect (OSTI)

    Urakaev, F.K. [Institute of Geology & Mineral SB RAS, Novosibirsk (Russian Federation)

    2009-04-15

    The regularities of the reversible reaction of isomerization of ammonium thiocyanate (NH{sub 4}NCS) into thiourea (NH{sub 2}){sub 2}CS, and the reverse reaction, were analyzed. An ecologically clean and highly efficient method for the extraction, purification, separation, and production of isomers from the coal byproduct ammonium thiocyanate was developed based on the measured volatilities of NH{sub 4}NCS and (NH{sub 2}){sub 2}CS.

  19. A simplified method for obtaining high-purity perchlorate from groundwater for isotope analyses.

    SciTech Connect (OSTI)

    vonKiparski, G; Hillegonds, D

    2011-04-04

    Investigations into the occurrence and origin of perchlorate (ClO{sub 4}{sup -}) found in groundwater from across North America have been sparse until recent years, and there is mounting evidence that natural formation mechanisms are important. New opportunities for identifying groundwater perchlorate and its origin have arisen with the utilization of improved detection methods and sampling techniques. Additionally, application of the forensic potential of isotopic measurements has begun to elucidate sources, potential formation mechanisms and natural attenuation processes. Procedures developed appear to be amenable to enable high precision stable isotopic analyses, as well as lower precision AMS analyses of {sup 36}Cl. Immediate work is in analyzing perchlorate isotope standards and developing full analytical accuracy and uncertainty expectations. Field samples have also been collected, and will be analyzed when final qa/qc samples are deemed acceptable.

  20. Experimental Demonstration of Advanced Palladium Membrane Separators for Central High Purity Hydrogen Production

    SciTech Connect (OSTI)

    Sean Emerson; Neal Magdefrau; Susanne Opalka; Ying She; Catherine Thibaud-Erkey; Thoman Vanderspurt; Rhonda Willigan

    2010-06-30

    The overall objectives for this project were to: (1) confirm the high stability and resistance of a PdCu trimetallic alloy to carbon and carbide formation and, in addition, resistance to sulfur, halides, and ammonia; (2) develop a sulfur, halide, and ammonia resistant alloy membrane with a projected hydrogen permeance of 25 m{sup 3}m{sup -2}atm{sup -0.5}h{sup -1} at 400 C and capable of operating at pressures of 12.1 MPa ({approx}120 atm, 1750 psia); and (3) construct and experimentally validate the performance of 0.1 kg/day H{sup 2} PdCu trimetallic alloy membrane separators at feed pressures of 2 MPa (290 psia) in the presence of H{sub 2}S, NH{sub 3}, and HCl. This project successfully increased the technology readiness level of palladium-based metallic membranes for hydrogen separation from coal-biomass gasifier exhaust or similar hydrogen-containing gas streams. The reversible tolerance of palladium-copper (PdCu) alloys was demonstrated for H{sub 2}S concentrations varying from 20 ppmv up to 487 ppmv and NH{sub 3} concentrations up to 9 ppmv. In addition, atomistic modeling validated the resistance of PdCu alloys to carbon formation, irreversible sulfur corrosion, and chlorine attack. The experimental program highlighted two key issues which must be addressed as part of future experimental programs: (1) tube defects and (2) non-membrane materials of construction. Four out of five FCC PdCu separators developed leaks during the course of the experimental program because {approx}10% of the alloy tubes contained a single defect that resulted in a thin, weak point in the tube walls. These defects limited operation of the existing tubes to less than 220 psig. For commercial applications of a PdCu alloy hydrogen separator under high sulfur concentrations, it was determined that stainless steel 316 is not suitable for housing or supporting the device. Testing with sulfur concentrations of 487 {+-} 4 ppmv resulted in severe corrosion of the stainless steel components of the separators. The project identified an experimental methodology for quantifying the impact of gas contaminants on PdCu alloy membrane performance as well as an atomistic modeling approach to screen metal alloys for their resistance to irreversible sulfur corrosion. Initial mathematical descriptions of the effect of species such as CO and H{sub 2}S were developed, but require further experimental work to refine. At the end of the project, an improvement to the experimental approach for acquiring the necessary data for the permeability model was demonstrated in preliminary tests on an enhanced PdCu separator. All of the key DOE 2010 technical targets were met or exceeded except for the hydrogen flux. The highest flux observed for the project, 125 ft{sup 3}ft{sup -2}h{sup -1}, was obtained on a single tube separator with the aforementioned enhanced PdCu separator with a hydrogen feed pressure of 185 psig at 500 C.

  1. Design, construction, and operation of a laboratory scale reactorfor the production of high-purity, isotopically enriched bulksilicon

    SciTech Connect (OSTI)

    Ager III, J.W.; Beeman, J.W.; Hansen, W.L.; Haller, E.E.

    2004-12-20

    The design and operation of a recirculating flow reactor designed to convert isotopically enriched silane to polycrystalline Si with high efficiency and chemical purity is described. The starting material is SiF{sub 4}, which is enriched in the desired isotope by a centrifuge method and subsequently converted to silane. In the reactor, the silane is decomposed to silicon on the surface of a graphite starter rod (3 mm diameter) heated to 700-750 C. Flow and gas composition (0.3-0.5% silane in hydrogen) are chosen to minimize the generation of particles by homogeneous nucleation of silane and to attain uniform deposition along the length of the rod. Growth rates are 5 {micro}m/min, and the conversion efficiency is greater than 95%. A typical run produces 35 gm of polycrystalline Si deposited along a 150 mm length of the rod. After removal of the starter rod, dislocation-free single crystals are formed by the floating zone method. Crystals enriched in all 3 stable isotopes of Si have been made: {sup 28}Si (99.92%), {sup 29}Si (91.37%), and {sup 30}Si (88.25%). Concentrations of electrically active impurities (P and B) are as low as mid-10{sup 13} cm{sup -3}. Concentrations of C and O lie below 10{sup 16} and 10{sup 15} cm{sup -3}, respectively.

  2. Commercialization of germanium based nanocrystal memory

    E-Print Network [OSTI]

    Seow, Kian Chiew

    2007-01-01

    This thesis explores the commercialization of germanium-based nanocrystal memories. Demand for smaller and faster electronics and embedded systems supports the development of high-density, low-power non-volatile electronic ...

  3. Measurement of the high-field Q-drop in a high-purity large-grain niobium cavity for different oxidation processes

    SciTech Connect (OSTI)

    Gianluigi Ciovati; Peter Kneisel; alex gurevich

    2007-06-01

    The most challenging issue for understanding the performance of superconducting radio-frequency (rf) cavities made of high-purity (residual resistivity ratio > 200) niobium is due to a sharp degradation (“Q-drop”) of the cavity quality factor Q0(Bp) as the peak surface magnetic field (Bp) exceeds about 90 mT, in the absence of field emission. In addition, a low-temperature (100 – 140 ?C) “in-situ” baking of the cavity was found to be beneficial in reducing the Q-drop. In this contribution, we present the results from a series of rf tests at 1.7 K and 2.0 K on a single-cell cavity made of high-purity large (with area of the order of few cm2) grain niobium which underwent various oxidation processes, after initial buffered chemical polishing, such as anodization, baking in pure oxygen atmosphere and baking in air up to 180 °C, with the objective of clearly identifying the role of oxygen and the oxide layer on the Q-drop. During each rf test a temperature mapping system allows measuring the local temperature rise of the cavity outer surface due to rf losses, which gives information about the losses location, their field dependence and space distribution. The results confirmed that the depth affected by baking is about 20 – 30 nm from the surface and showed that the Q-drop did not re-appear in a previously baked cavity by further baking at 120 °C in pure oxygen atmosphere or in air up to 180 °C. These treatments increased the oxide thickness and oxygen concentration, measured on niobium samples which were processed with the cavity and were analyzed with Transmission Electron Microscope (TEM) and Secondary Ion Mass Spectroscopy (SIMS). Nevertheless, the performance of the cavity after air baking at 180 °C degraded significantly and the temperature maps showed high losses, uniformly distributed on the surface, which could be completely recovered only by a post-purification treatment at 1250 °C. A statistic of the position of the “hot-spots” on the cavity surface showed that grain-boundaries are not the preferred location. An interesting correlation was found between the Q-drop onset, the quench field and the low-field energy gap, which supports the hypothesis of thermo-magnetic instability governing the Q-drop and the baking effect.

  4. Germanium detector passivated with hydrogenated amorphous germanium

    DOE Patents [OSTI]

    Hansen, William L. (Walnut Creek, CA); Haller, Eugene E. (Berkeley, CA)

    1986-01-01

    Passivation of predominantly crystalline semiconductor devices (12) is provided for by a surface coating (21) of sputtered hydrogenated amorphous semiconductor material. Passivation of a radiation detector germanium diode, for example, is realized by sputtering a coating (21) of amorphous germanium onto the etched and quenched diode surface (11) in a low pressure atmosphere of hydrogen and argon. Unlike prior germanium diode semiconductor devices (12), which must be maintained in vacuum at cryogenic temperatures to avoid deterioration, a diode processed in the described manner may be stored in air at room temperature or otherwise exposed to a variety of environmental conditions. The coating (21) compensates for pre-existing undesirable surface states as well as protecting the semiconductor device (12) against future impregnation with impurities.

  5. RADIATION DAMAGE OF GERMANIUM DETECTORS

    E-Print Network [OSTI]

    Pehl, Richard H.

    2011-01-01

    occurring within the detector, radiation may also change theLBL-7967 RADIATION DAMAGE OF GERMANIUM DETECTORS Richard H.LBL-7967 RADIATION DAMAGE OF GERMANIUM DETECTORS* Richard H.

  6. Germanium: From Its Discovery to SiGe Devices

    SciTech Connect (OSTI)

    Haller, E.E.

    2006-06-14

    Germanium, element No.32, was discovered in 1886 by Clemens Winkler. Its first broad application was in the form of point contact Schottky diodes for radar reception during WWII. The addition of a closely spaced second contact led to the first all-solid-state electronic amplifier device, the transistor. The relatively low bandgap, the lack of a stable oxide and large surface state densities relegated germanium to the number 2 position behind silicon. The discovery of the lithium drift process, which made possible the formation of p-i-n diodes with fully depletable i-regions several centimeters thick, led germanium to new prominence as the premier gamma-ray detector. The development of ultra-pure germanium yielded highly stable detectors which have remained unsurpassed in their performance. New acceptors and donors were discovered and the electrically active role of hydrogen was clearly established several years before similar findings in silicon. Lightly doped germanium has found applications as far infrared detectors and heavily Neutron Transmutation Doped (NTD) germanium is used in thermistor devices operating at a few milliKelvin. Recently germanium has been rediscovered by the silicon device community because of its superior electron and hole mobility and its ability to induce strains when alloyed with silicon. Germanium is again a mainstream electronic material.

  7. The production of ultra-high purity single isotopes or tailored isotope mixtures by ICP-MS

    SciTech Connect (OSTI)

    Liezers, Martin; Farmer, Orville T.; Dion, Michael P.; Thomas, Linda MP; Eiden, Gregory C.

    2015-01-01

    We report the development and testing of a simple collector arrangement for a commercial quadrupole ICP-MS that for the first time has been used to produce small quantities of highly enriched (>99.99%) single isotopes, with deposition rates >10 ng/hour. The collector assembly replaces the standard instrument detector allowing for implantation with simultaneous monitoring of the incident ion current. Even under zero bias implant conditions, low energy (<10 eV), ion collection efficiency was observed to be very high ~99%. 151Eu ion currents of 0.1-0.5 nA were collected on a simple, planar foil without resorting to any type of cup configuration. Recovery of the enriched isotope from such foils is much simpler than from a more complex cup configuration. High rejection of adjacent mass isotopes was demonstrated by selectively implanting 167Er without any discernible co-implantation of 166Er and 168Er. The important analytical possibilities of the new approach to isotope ratio measurement, tracer purification and radiation measurements are discussed.

  8. Robust Low-Cost Water-Gas Shift Membrane Reactor for High-Purity Hydrogen Production form Coal-Derived Syngas

    SciTech Connect (OSTI)

    James Torkelson; Neng Ye; Zhijiang Li; Decio Coutinho; Mark Fokema

    2008-05-31

    This report details work performed in an effort to develop a low-cost, robust water gas shift membrane reactor to convert coal-derived syngas into high purity hydrogen. A sulfur- and halide-tolerant water gas shift catalyst and a sulfur-tolerant dense metallic hydrogen-permeable membrane were developed. The materials were integrated into a water gas shift membrane reactor in order to demonstrate the production of >99.97% pure hydrogen from a simulated coal-derived syngas stream containing 2000 ppm hydrogen sulfide. The objectives of the program were to (1) develop a contaminant-tolerant water gas shift catalyst that is able to achieve equilibrium carbon monoxide conversion at high space velocity and low steam to carbon monoxide ratio, (2) develop a contaminant-tolerant hydrogen-permeable membrane with a higher permeability than palladium, (3) demonstrate 1 L/h purified hydrogen production from coal-derived syngas in an integrated catalytic membrane reactor, and (4) conduct a cost analysis of the developed technology.

  9. Measurement of the dielectric properties of high-purity sapphire at 1.865 GHZ from 2-10 Kelvin

    SciTech Connect (OSTI)

    N. Pogue, P. McIntyre, Akhdiyor Sattarov, Charles Reece

    2012-06-01

    A dielectric test cavity was designed and tested to measure the microwave dielectric properties of ultrapure sapphire at cryogenic temperatures. Measurements were performed by placing a large cylindrical crystal of sapphire in a Nb superconducting cavity operating in the TE01 mode at 1.865 GHz. The dielectric constant, heat capacity, and loss tangent were all calculated using experimental data and RF modeling software. The motivation for these measurements was to determine if such a sapphire could be used as a dielectric lens to focus the magnetic field onto a sample wafer in a high field wafer test cavity. The measured properties have been used to finalize the design of the wafer test cavity.

  10. Astroparticle physics with a customized low-background broad energy Germanium detector

    SciTech Connect (OSTI)

    Aalseth, Craig E.; Amman, M.; Avignone, Frank T.; Back, Henning O.; Barabash, Alexander S.; Barbeau, P. S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Bugg, William; Burritt, Tom H.; Busch, Matthew; Capps, Greg L.; Chan, Yuen-Dat; Collar, J. I.; Cooper, R. J.; Creswick, R.; Detwiler, Jason A.; Diaz, J.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, Steven R.; Ely, James H.; Esterline, James H.; Farach, H. A.; Fast, James E.; Fields, N.; Finnerty, P.; Fujikawa, Brian; Fuller, Erin S.; Gehman, Victor M.; Giovanetti, G. K.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Harper, Gregory; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Hossbach, Todd W.; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keillor, Martin E.; Keller, C.; Kephart, Jeremy D.; Kidd, Mary; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Leviner, L.; Loach, J. C.; Luke, P.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Mei, Dong-Ming; Miley, Harry S.; Miller, M. L.; Mizouni, Leila; Myers, Allan W.; Nomachi, Masaharu; Orrell, John L.; Peterson, David; Phillips, D.; Poon, Alan; Prior, Gersende; Qian, J.; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Rodriguez, Larry; Rykaczewski, Krzysztof P.; Salazar, Harold; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Steele, David; Strain, J.; Swift, Gary; Thomas, K.; Timkin, V.; Tornow, W.; Van Wechel, T. D.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Wilkerson, J. F.; Wolfe, B. A.; Xiang, W.; Yakushev, E.; Yaver, Harold; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C.; Zimmerman, S.

    2011-10-01

    The Majorana Collaboration is building the Majorana Demonstrator, a 60 kg array of high purity germanium detectors housed in an ultra-low background shield at the Sanford Underground Laboratory in Lead, SD. The Majorana Demonstrator will search for neutrinoless double-beta decay of 76Ge while demonstrating the feasibility of a tonne-scale experiment. It may also carry out a dark matter search in the 1-10 GeV/c² mass range. We have found that customized Broad Energy Germanium (BEGe) detectors produced by Canberra have several desirable features for a neutrinoless double-beta decay experiment, including low electronic noise, excellent pulse shape analysis capabilities, and simple fabrication. We have deployed a customized BEGe, the Majorana Low-Background BEGe at Kimballton (MALBEK), in a low-background cryostat and shield at the Kimballton Underground Research Facility in Virginia. This paper will focus on the detector characteristics and measurements that can be performed with such a radiation detector in a low-background environment.

  11. Use of Electrodeposition for Sample Preparation and Rejection Rate Prediction for Assay of Electroformed Ultra High Purity Copper for 232Th and 238U Prior to Inductively Coupled Plasma Mass Spectrometry (ICP/MS)

    SciTech Connect (OSTI)

    Hoppe, Eric W.; Aalseth, Craig E.; Brodzinski, Ronald L.; Day, Anthony R.; Farmer, Orville T.; Hossbach, Todd W.; McIntyre, Justin I.; Miley, Harry S.; Mintzer, Esther E.; Seifert, Allen; Smart, John E.; Warren, Glen A.

    2008-07-01

    The search for neutrinoless double beta decay in 76Ge has driven the need for ultra-low background Ge detectors shielded by electroformed copper of ultra-high radiopurity (<0.1µBq/kg). Although electrodeposition processes are almost sophisticated enough to produce copper of this purity, to date there are no methods sensitive enough to assay it. Inductively-coupled plasma mass spectrometry (ICP/MS) can detect thorium and uranium at femtogram levels, but in the past, this assay has been hindered by high copper concentrations in the sample. Electrodeposition of copper samples removes copper from the solution while selectively concentrating thorium and uranium contaminants to be assayed by ICP/MS. Spiking 232Th and 238U into the plating bath simulates low purity copper and allows for the calculation of the electrochemical rejection rate of thorium and uranium in the electroplating system. This rejection value will help to model plating bath chemistry.

  12. Germanium films by polymer-assisted deposition

    DOE Patents [OSTI]

    Jia, Quanxi; Burrell, Anthony K.; Bauer, Eve; Ronning, Filip; McCleskey, Thomas Mark; Zou, Guifu

    2013-01-15

    Highly ordered Ge films are prepared directly on single crystal Si substrates by applying an aqueous coating solution having Ge-bound polymer onto the substrate and then heating in a hydrogen-containing atmosphere. A coating solution was prepared by mixing water, a germanium compound, ethylenediaminetetraacetic acid, and polyethyleneimine to form a first aqueous solution and then subjecting the first aqueous solution to ultrafiltration.

  13. Identification of photons in double beta-decay experiments using segmented germanium detectors - studies with a GERDA Phase II prototype detector

    E-Print Network [OSTI]

    I. Abt; A. Caldwell; K. Kröninger; J. Liu; X. Liu; B. Majorovits

    2007-01-04

    The sensitivity of experiments searching for neutrinoless double beta-decay of germanium was so far limited by the background induced by external gamma-radiation. Segmented germanium detectors can be used to identify photons and thus reduce this background component. The GERmanium Detector Array, GERDA, will use highly segmented germanium detectors in its second phase. The identification of photonic events is investigated using a prototype detector. The results are compared with Monte Carlo data.

  14. Preparation of High Purity, High Molecular-Weight Chitin from Ionic Liquids for Use as an Adsorbate for the Extraction of Uranium from Seawater (Workscope MS-FC: Fuel Cycle R&D)

    SciTech Connect (OSTI)

    Rogers, Robin

    2013-12-21

    Ensuring a domestic supply of uranium is a key issue facing the wider implementation of nuclear power. Uranium is mostly mined in Kazakhstan, Australia, and Canada, and there are few high-grade uranium reserves left worldwide. Therefore, one of the most appealing potential sources of uranium is the vast quantity dissolved in the oceans (estimated to be 4.4 billion tons worldwide). There have been research efforts centered on finding a means to extract uranium from seawater for decades, but so far none have resulted in an economically viable product, due in part to the fact that the materials that have been successfully demonstrated to date are too costly (in terms of money and energy) to produce on the necessary scale. Ionic Liquids (salts which melt below 100{degrees}C) can completely dissolve raw crustacean shells, leading to recovery of a high purity, high molecular weight chitin powder and to fibers and films which can be spun directly from the extract solution suggesting that continuous processing might be feasible. The work proposed here will utilize the unprecedented control this makes possible over the chitin fiber a) to prepare electrospun nanofibers of very high surface area and in specific architectures, b) to modify the fiber surfaces chemically with selective extractant capacity, and c) to demonstrate their utility in the direct extraction and recovery of uranium from seawater. This approach will 1) provide direct extraction of chitin from shellfish waste thus saving energy over the current industrial process for obtaining chitin; 2) allow continuous processing of nanofibers for very high surface area fibers in an economical operation; 3) provide a unique high molecular weight chitin not available from the current industrial process leading to stronger, more durable fibers; and 4) allow easy chemical modification of the large surface areas of the fibers for appending uranyl selective functionality providing selectivity and ease of stripping. The resulting sorbent should prove economically feasible, as well as providing an overall net energy gain.

  15. GERMANIUM--2001 32.1 By Robert D. Brown, Jr.

    E-Print Network [OSTI]

    GERMANIUM--2001 32.1 GERMANIUM By Robert D. Brown, Jr. Domestic survey data and table were prepared. In 2001, the domestic germanium industry consisted of two zinc mining operations in Alaska and Tennessee of germanium was estimated to have remained about the same in 2001. The USGS estimated domestic germanium

  16. The Majorana Demonstrator: A search for neutrinoless double-beta decay of germanium-76

    SciTech Connect (OSTI)

    Elliott, S. R.; Boswell, M.; Goett, J.; Rielage, K.; Ronquest, M. C.; Xu, W. [Los Alamos National Laboratory, Los Alamos, NM (United States); Abgrall, N.; Chan, Y-D.; Hegai, A.; Martin, R. D.; Mertens, S.; Poon, A. W. P. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Aguayo, E.; Fast, J. E.; Hoppe, E. W.; Kouzes, R. T.; LaFerriere, B. D.; Orrell, J. L.; Overman, N. R.; Soin, A. [Pacific Northwest National Laboratory, Richland, WA (United States); and others

    2013-12-30

    The MAJORANA collaboration is searching for neutrinoless double beta decay using {sup 76}Ge, which has been shown to have a number of advantages in terms of sensitivities and backgrounds. The observation of neutrinoless double-beta decay would show that lepton number is violated and that neutrinos are Majorana particles and would simultaneously provide information on neutrino mass. Attaining sensitivities for neutrino masses in the inverted hierarchy region, 15 - 50 meV, will require large, tonne-scale detectors with extremely low backgrounds, at the level of ?1 count/t-y or lower in the region of the signal. The MAJORANA collaboration, with funding support from DOE Office of Nuclear Physics and NSF Particle Astrophysics, is constructing the DEMONSTRATOR, an array consisting of 40 kg of p-type point-contact high-purity germanium (HPGe) detectors, of which ?30 kg will be enriched to 87% in {sup 76}Ge. The DEMONSTRATOR is being constructed in a clean room laboratory facility at the 4850' level (4300 m.w.e.) of the Sanford Underground Research Facility (SURF) in Lead, SD. It utilizes a compact graded shield approach with the inner portion consisting of ultra-clean Cu that is being electroformed and machined underground. The primary aim of the DEMONSTRATOR is to show the feasibility of a future tonne-scale measurement in terms of backgrounds and scalability.

  17. Bridged polygermsesquioxanes. Organically modified germanium oxide materials

    SciTech Connect (OSTI)

    Jamison, G.M.; Loy, D.A. (Sandia National Labs., Albuquerque, NM (United States)); Shea, K.J. (Univ. of California, Irvine, CA (United States))

    1993-09-01

    Sol-gel processed polysilsesquioxanes are hybrid organic-inorganic materials with potential applications as photoresists, membranes, or catalytic supports. Hydrolytic conversion of trichloro- or trialkoxysilanes often leads to amorphous or crystalline oligosilsesquioxanes instead of high polymers. In light of the intimate dependence of polysilsesquioxane properties of tightly controlled reaction conditions and processing, recent emphasis has been placed on control of polymer microarchitecture via the introduction of arylene-, acetylene-, and alkylene-bridging groups. Another strategy for modifying the properties of hybrid organic-inorganic polymers is to substitute a group IVA metal, such as germanium, for silicon. The authors report the synthesis and characterization of bifunctional hexylene-bridged organogermanium monomers X[sub 3]Ge-(CH[sub 2])[sub 6]GeX[sub 3] (X = Cl; OEt) and the formation of polymeric materials through sol-gel hydrolysis-condensation of the monomers. 15 refs., 2 figs.

  18. Astroparticle physics with a customized low-background broad...

    Office of Scientific and Technical Information (OSTI)

    low-background broad energy Germanium detector The Majorana Collaboration is building the Majorana Demonstrator, a 60 kg array of high purity germanium detectors housed in...

  19. Mechanically Cooled Large-Volume Germanium Detector Systems for Neclear Explosion Monitoring DOENA27323-2

    SciTech Connect (OSTI)

    Hull, E.L.

    2006-10-30

    Compact maintenance free mechanical cooling systems are being developed to operate large volume high-resolution gamma-ray detectors for field applications. To accomplish this we are utilizing a newly available generation of Stirling-cycle mechanical coolers to operate the very largest volume germanium detectors with no maintenance. The user will be able to leave these systems unplugged on the shelf until needed. The maintenance-free operating lifetime of these detector systems will exceed 5 years. Three important factors affect the operation of mechanically cooled germanium detectors: temperature, vacuum, and vibration. These factors will be studied in the laboratory at the most fundamental levels to insure a solid understanding of the physical limitations each factor places on a practical mechanically cooled germanium detector system. Using this knowledge, mechanically cooled germanium detector prototype systems will be designed and fabricated.

  20. GERMANIUM--1999 32.1 By Robert D. Brown

    E-Print Network [OSTI]

    GERMANIUM--1999 32.1 GERMANIUM By Robert D. Brown Domestic survey data and table were prepared. In 1999, the domestic germanium industry consisted of two zinc mining operations in Alaska and Tennessee in 1999, but U.S. consumption has remained steady for 3 years. The USGS estimated domestic germanium

  1. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01

    Application in High Efficiency Multi-Junction Solar Cells AApplication in High Efficiency Multi-Junction Solar Cells Bycost of high efficiency multi-junction solar cells through a

  2. Solution synthesis of germanium nanocrystals

    DOE Patents [OSTI]

    Gerung, Henry (Albuquerque, NM); Boyle, Timothy J. (Kensington, MD); Bunge, Scott D. (Cuyahoga Falls, OH)

    2009-09-22

    A method for providing a route for the synthesis of a Ge(0) nanometer-sized material from. A Ge(II) precursor is dissolved in a ligand heated to a temperature, generally between approximately 100.degree. C. and 400.degree. C., sufficient to thermally reduce the Ge(II) to Ge(0), where the ligand is a compound that can bond to the surface of the germanium nanomaterials to subsequently prevent agglomeration of the nanomaterials. The ligand encapsulates the surface of the Ge(0) material to prevent agglomeration. The resulting solution is cooled for handling, with the cooling characteristics useful in controlling the size and size distribution of the Ge(0) materials. The characteristics of the Ge(II) precursor determine whether the Ge(0) materials that result will be nanocrystals or nanowires.

  3. \\textsc{MaGe} - a {\\sc Geant4}-based Monte Carlo Application Framework for Low-background Germanium Experiments

    E-Print Network [OSTI]

    Melissa Boswell; Yuen-Dat Chan; Jason A. Detwiler; Padraic Finnerty; Reyco Henning; Victor M. Gehman; Rob A. Johnson; David V. Jordan; Kareem Kazkaz; Markus Knapp; Kevin Kröninger; Daniel Lenz; Lance Leviner; Jing Liu; Xiang Liu; Sean MacMullin; Michael G. Marino; Akbar Mokhtarani; Luciano Pandola; Alexis G. Schubert; Jens Schubert; Claudia Tomei; Oleksandr Volynets

    2010-11-16

    We describe a physics simulation software framework, MAGE, that is based on the GEANT4 simulation toolkit. MAGE is used to simulate the response of ultra-low radioactive background radiation detectors to ionizing radiation, specifically the MAJORANA and GERDA neutrinoless double-beta decay experiments. MAJORANA and GERDA use high-purity germanium detectors to search for the neutrinoless double-beta decay of 76Ge, and MAGE is jointly developed between these two collaborations. The MAGE framework contains the geometry models of common objects, prototypes, test stands, and the actual experiments. It also implements customized event generators, GEANT4 physics lists, and output formats. All of these features are available as class libraries that are typically compiled into a single executable. The user selects the particular experimental setup implementation at run-time via macros. The combination of all these common classes into one framework reduces duplication of efforts, eases comparison between simulated data and experiment, and simplifies the addition of new detectors to be simulated. This paper focuses on the software framework, custom event generators, and physics lists.

  4. MaGe - a GEANT4-based Monte Carlo Application Framework for Low-background Germanium Experiments

    SciTech Connect (OSTI)

    Boswell, M.; Chan, Yuen-Dat; Detwiler, Jason A.; Finnerty, P.; Henning, R.; Gehman, Victor; Johnson, Robert A.; Jordan, David V.; Kazkaz, Kareem; Knapp, Markus; Kroninger, Kevin; Lenz, Daniel; Leviner, L.; Liu, Jing; Liu, Xiang; MacMullin, S.; Marino, Michael G.; Mokhtarani, A.; Pandola, Luciano; Schubert, Alexis G.; Schubert, J.; Tomei, Claudia; Volynets, Oleksandr

    2011-06-13

    We describe a physics simulation software framework, MAGE, that is based on the GEANT4 simulation toolkit. MAGE is used to simulate the response of ultra-low radioactive background radiation detectors to ionizing radiation, speci?cally the MAJ ORANA and GE RDA neutrinoless double-beta decay experiments. MAJ ORANA and GERDA use high-purity germanium technology to search for the neutrinoless double-beta decay of the 76 Ge isotope, and MAGE is jointly developed between these two collaborations. The MAGE framework contains simulated geometries of common objects, prototypes, test stands, and the actual experiments. It also implements customized event generators, GE ANT 4 physics lists, and output formats. All of these features are available as class libraries that are typically compiled into a single executable. The user selects the particular experimental setup implementation at run-time via macros. The combination of all these common classes into one framework reduces duplication of efforts, eases comparison between simulated data and experiment, and simpli?es the addition of new detectors to be simulated. This paper focuses on the software framework, custom event generators, and physics list.

  5. Study of Phonon Modes in Germanium Nanowires

    E-Print Network [OSTI]

    Xi Wang; Ali Shakouri; Bin Yu; Xuhui Sun; Meyya Meyyappan

    2007-02-25

    The observation of pure phonon confinement effect in germanium nanowires is limited due to the illumination sensitivity of Raman spectra. In this paper we measured Raman spectra for different size germanium nanowires with different excitation laser powers and wavelengths. By eliminating the local heating effect, the phonon confinement effect for small size nanowires was clearly identified. We have also fitted the Raman feature changes to estimate the size distribution of nanowires for the first time.

  6. Optical properties of colloidal germanium nanocrystals

    SciTech Connect (OSTI)

    WILCOXON,JESS P.; PROVENCIO,PAULA P.; SAMARA,GEORGE A.

    2000-05-01

    Highly crystalline germanium (Ge) nanocrystals in the size range 2--10 nm were grown in inverse micelles and purified and size-separated by high pressure liquid chromatography with on-line optical and electrical diagnostics. The nanocrystals retain the diamond structure of bulk Ge down to at least 2.0 nm (containing about 150 Ge atoms). The background- and impurity-free extinction and photoluminescence (PL) spectra of these nanocrystals revealed rich structure which was interpreted in terms of the bandstructure of Ge shifted to higher energies by quantum confinement. The shifts ranged from {minus}0.1 eV to over 1 eV for the various transitions. PL in the range 350--700 nm was observed from nanocrystals 2--5 nm in size. The 2.0 nm nanocrystals yielded the most intense PL (at 420 nm) which is believed to be intrinsic and attributed to direct recombination at {Gamma}. Excitation at high energy (250 nm) populates most of the conduction bands resulting in competing recombination channels and the observed broad PL spectra.

  7. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01

    Efficiency Multi-Junction Solar Cells A thesis submitted inHigh Efficiency Multi-Junction Solar Cells By David Michaelsubstrate costs of multi-junction solar cells by recycling

  8. FABRICATION TECHNIQUES FOR REVERSE ELECTRODE COAXIAL GERMANIUM NUCLEAR RADIATION DETECTORS

    E-Print Network [OSTI]

    Hansen, W.L.

    2010-01-01

    GERMANIUM NUCLEAR RADIATION DETECTORS W.L. Hansen and E.E.Semiconductor Nuclear Radiation Detectors", IEEE Trans. Nuc.GERMANIUM NUCLEAR RADIATION DETECTORS LBL-10726 W. L. Hansen

  9. Recovery of germanium-68 from irradiated targets

    DOE Patents [OSTI]

    Phillips, Dennis R. (Los Alamos, NM); Jamriska, Sr., David J. (Los Alamos, NM); Hamilton, Virginia T. (Los Alamos, NM)

    1993-01-01

    A process for selective separation of germanium-68 from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected from the group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the first resin, adjusting the pH of the second ion-containing solution to within a range of from about 0.7 to about 3.0, adjusting the soluble metal halide concentration in the second ion-containing solution to a level adapted for subsequent separation of germanium, contacting the pH-adjusted, soluble metal halide-containing second ion-containing solution with a dextran-based material whereby germanium ions are separated by the dextran-based material, and recovering the germanium from the dextran-based material, preferably by distillation.

  10. Germanium-induced stabilization of a very high-k zirconia phase in ZrO{sub 2}/GeO{sub 2} gate stacks

    SciTech Connect (OSTI)

    Tsipas, P.; Volkos, S. N.; Sotiropoulos, A.; Galata, S. F.; Mavrou, G.; Tsoutsou, D.; Panayiotatos, Y.; Dimoulas, A.; Marchiori, C.; Fompeyrine, J.

    2008-08-25

    Electrical data on ZrO{sub 2}/GeO{sub 2} stacks prepared by atomic oxygen beam deposition on Ge at 225 deg. C reveal a relatively weak dependence of the stack equivalent oxide thickness upon the ZrO{sub 2} thickness. This trend points to a very high zirconia dielectric permittivity (k) value which is estimated to be around 44. This is indicative of zirconia crystallization into a tetragonal phase which is also supported by x-ray diffraction data. X-ray photoelectron spectroscopy analysis is in line with the assumption that due to a finite GeO{sub 2} decomposition, Ge is incorporated into the growing ZrO{sub 2}, thus, stabilizing the high-k tetragonal phase.

  11. Silicon And Silicon-germanium Epitaxy For Quantum Dot Device Fabrications

    E-Print Network [OSTI]

    as they provide highly tunable structures for trapping and manipu- lating individual electrons/silicon- germanium material heterosystem. We describe the growth of two-dimensional electron gas structures advisor Professor James C. Sturm, whose perpetual enthusiasm, stimulating insight, and constant

  12. Tensile strain mapping in flat germanium membranes

    SciTech Connect (OSTI)

    Rhead, S. D., E-mail: S.Rhead@warwick.ac.uk; Halpin, J. E.; Myronov, M.; Patchett, D. H.; Allred, P. S.; Wilson, N. R.; Leadley, D. R. [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Shah, V. A. [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Department of Engineering, University of Warwick, Coventry, CV4 7AL (United Kingdom); Kachkanov, V.; Dolbnya, I. P. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Reparaz, J. S. [ICN2 - Institut Catala de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona) (Spain); Sotomayor Torres, C. M. [ICN2 - Institut Catala de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona) (Spain)

    2014-04-28

    Scanning X-ray micro-diffraction has been used as a non-destructive probe of the local crystalline quality of a thin suspended germanium (Ge) membrane. A series of reciprocal space maps were obtained with ?4 ?m spatial resolution, from which detailed information on the strain distribution, thickness, and crystalline tilt of the membrane was obtained. We are able to detect a systematic strain variation across the membranes, but show that this is negligible in the context of using the membranes as platforms for further growth. In addition, we show evidence that the interface and surface quality is improved by suspending the Ge.

  13. Influence of Salt Purity on Na+ and Palmitic Acid Interactions

    E-Print Network [OSTI]

    Influence of Salt Purity on Na+ and Palmitic Acid Interactions Zishuai Huang, Wei Hua, Dominique of salt purity on the interactions between Na+ ions and the carboxylate (COO- ) head group of palmitic frequency generation (VSFG) spectroscopy. Ultrapure (UP) and ACS grade NaCl salts are used for aqueous

  14. Screening of the quantum-confined Stark effect in AlN/GaN nanowire superlattices by germanium doping

    SciTech Connect (OSTI)

    Hille, P. Müßener, J.; Becker, P.; Teubert, J.; Schörmann, J.; Eickhoff, M.; Mata, M. de la; Rosemann, N.; Chatterjee, S.; Magén, C.; Arbiol, J.; Institucio Catalana de Recerca i Estudis Avançats , 08010 Barcelona, CAT

    2014-03-10

    We report on electrostatic screening of polarization-induced internal electric fields in AlN/GaN nanowire heterostructures with germanium-doped GaN nanodiscs embedded between AlN barriers. The incorporation of germanium at concentrations above 10{sup 20}?cm{sup –3} shifts the photoluminescence emission energy of GaN nanodiscs to higher energies accompanied by a decrease of the photoluminescence decay time. At the same time, the thickness-dependent shift in emission energy is significantly reduced. In spite of the high donor concentration, a degradation of the photoluminescence properties is not observed.

  15. Actinium radioisotope products of enhanced purity

    DOE Patents [OSTI]

    Meikrantz, David Herbert; Todd, Terry Allen; Tranter, Troy Joseph; Horwitz, E. Philip

    2010-06-15

    A product includes actinium-225 (.sup.225Ac) and less than about 1 microgram (.mu.g) of iron (Fe) per millicurie (mCi) of actinium-225. The product may have a radioisotopic purity of greater than about 99.99 atomic percent (at %) actinium-225 and daughter isotopes of actinium-225, and may be formed by a method that includes providing a radioisotope mixture solution comprising at least one of uranium-233 (.sup.233U) and thorium-229 (.sup.229Th), extracting the at least one of uranium-233 and thorium-229 into an organic phase, substantially continuously contacting the organic phase with an aqueous phase, substantially continuously extracting actinium-225 into the aqueous phase, and purifying the actinium-225 from the aqueous phase. In some embodiments, the product may include less than about 1 nanogram (ng) of iron per millicurie (mCi) of actinium-225, and may include less than about 1 microgram (.mu.g) each of magnesium (Mg), Chromium (Cr), and manganese (Mn) per millicurie (mCi) of actinium-225.

  16. Electron spin coherence of shallow donors in natural and isotopically enriched germanium

    E-Print Network [OSTI]

    A. J. Sigillito; R. M. Jock; A. M. Tyryshkin; J. W. Beeman; E. E. Haller; K. M. Itoh; S. A. Lyon

    2015-11-07

    Germanium is a widely used material for electronic and optoelectronic devices and recently it has become an important material for spintronics and quantum computing applications. Donor spins in silicon have been shown to support very long coherence times ($T_{2}$) when the host material is isotopically enriched to remove any magnetic nuclei. Germanium also has non-magnetic isotopes so it is expected to support long $T_{2}$s while offering some new properties. Compared to Si, Ge has a strong spin-orbit coupling, large electron wavefunction, high mobility, and highly anisotropic conduction band valleys which will all give rise to new physics. In this Letter, the first pulsed electron spin resonance (ESR) measurements of $T_{2}$ and the spin-lattice relaxation ($T_1$) times for $^{75}$As and $^{31}$P donors in natural and isotopically enriched germanium are presented. We compare samples with various levels of isotopic enrichment and find that spectral diffusion due to $^{73}$Ge nuclear spins limits the coherence in samples with significant amounts of $^{73}$Ge. For the most highly enriched samples, we find that $T_1$ limits $T_2$ to $T_2 = 2T_1$. We report an anisotropy in $T_1$ and the ensemble linewidths for magnetic fields oriented along different crystal axes but do not resolve any angular dependence to the spectral-diffusion-limited $T_2$ in samples with $^{73}$Ge.

  17. Electron spin coherence of shallow donors in natural and isotopically enriched germanium

    E-Print Network [OSTI]

    A. J. Sigillito; R. M. Jock; A. M. Tyryshkin; J. W. Beeman; E. E. Haller; K. M. Itoh; S. A. Lyon

    2015-09-16

    Germanium is a widely used material for electronic and optoelectronic devices and recently it has become an important material for spintronics and quantum computing applications. Donor spins in silicon have been shown to support very long coherence times ($T_{2}$) when the host material is isotopically enriched to remove any magnetic nuclei. Germanium also has non-magnetic isotopes so it is expected to support long $T_{2}$s while offering some new properties. Compared to Si, Ge has a strong spin-orbit coupling, large electron wavefunction, high mobility, and highly anisotropic conduction band valleys which will all give rise to new physics. In this Letter, the first pulsed electron spin resonance (ESR) measurements of $T_{2}$ and the spin-lattice relaxation ($T_1$) times for $^{75}$As and $^{31}$P donors in natural and isotopically enriched germanium are presented. We compare samples with various levels of isotopic enrichment and find that spectral diffusion due to $^{73}$Ge nuclear spins limits the coherence in samples with significant amounts of $^{73}$Ge. For the most highly enriched samples, we find that $T_1$ limits $T_2$ to $T_2 = 2T_1$. We report an anisotropy in $T_1$ and the ensemble linewidths for magnetic fields oriented along different crystal axes but do not resolve any angular dependence to the spectral-diffusion-limited $T_2$ in samples with $^{73}$Ge.

  18. Empirical Correction of Crosstalk in a Low-Background Germanium ?–? Analysis System

    SciTech Connect (OSTI)

    Keillor, Martin E.; Erikson, Luke E.; Aalseth, Craig E.; Day, Anthony R.; Fuller, Erin S.; Glasgow, Brian D.; Hoppe, Eric W.; Hossbach, Todd W.; Mizouni, Leila K.; Myers, Allan W.; Overman, Cory T.; Seifert, Allen; Stavenger, Timothy J.

    2013-05-01

    ABSTRACT The Pacific Northwest National Laboratory is currently developing a custom software suite capable of automating many of the tasks required to accurately analyze coincident signals within gamma spectrometer arrays. During the course of this work, significant crosstalk was identified in the energy determination for spectra collected with a new low-background intrinsic germanium (HPGe) array at PNNL. The HPGe array is designed for high detection efficiency, ultra-low-background performance, and sensitive gamma gamma coincidence detection. The first half of the array, a single cryostat containing 7 HPGe crystals, was recently installed into a new shallow underground laboratory facility. This update will present a brief review of the germanium array, describe the observed crosstalk, and present a straight-forward empirical correction that significantly reduces the impact of this crosstalk on the spectroscopic performance of the system.

  19. Loss of purity by wave packet scattering at low energies

    E-Print Network [OSTI]

    Jia Wang; C. K. Law; M. -C. Chu

    2006-01-06

    We study the quantum entanglement produced by a head-on collision between two gaussian wave packets in three-dimensional space. By deriving the two-particle wave function modified by s-wave scattering amplitudes, we obtain an approximate analytic expression of the purity of an individual particle. The loss of purity provides an indicator of the degree of entanglement. In the case the wave packets are narrow in momentum space, we show that the loss of purity is solely controlled by the ratio of the scattering cross section to the transverse area of the wave packets.

  20. Flaw-limited transport in germanium-on-silicon photodiodes

    E-Print Network [OSTI]

    Orcutt, Jason S. (Jason Scott)

    2008-01-01

    Epitaxial germanium growth on silicon substrates has enabled a new class of photodiodes that can be integrated with traditional silicon electronics. Previous workers using lowthroughput growth techniques have demonstrated ...

  1. Neutron Interactions as Seen by A Segmented Germanium Detector

    E-Print Network [OSTI]

    I. Abt; A. Caldwell; K. Kroeninger; J. Liu; X. Liu; B. Majorovits

    2007-11-14

    The GERmanium Detector Array, GERDA, is designed for the search for ``neutrinoless double beta decay'' (0-nu-2-beta) with germanium detectors enriched in Ge76. An 18-fold segmented prototype detector for GERDA Phase II was exposed to an AmBe neutron source to improve the understanding of neutron induced backgrounds. Neutron interactions with the germanium isotopes themselves and in the surrounding materials were studied. Segment information is used to identify neutron induced peaks in the recorded energy spectra. The Geant4 based simulation package MaGe is used to simulate the experiment. Though many photon peaks from germanium isotopes excited by neutrons are correctly described by Geant4, some physics processes were identified as being incorrectly treated or even missing.

  2. Maximum likelihood analysis of low energy CDMS II germanium data

    E-Print Network [OSTI]

    2015-01-01

    likelihood analysis of low energy CDMS II germanium data R.United States Department of Energy, by NSERC Canada, and byStates Department of Energy. [1] P. A. R. Ade et al. (Planck

  3. Tunnel current across linear homocatenated germanium chains

    SciTech Connect (OSTI)

    Matsuura, Yukihito, E-mail: matsuura@chem.nara-k.ac.jp [Department of Chemical Engineering, Nara National College of Technology Yatacho 22, Yamato-koriyama, Nara 539-1080 (Japan)

    2014-01-28

    The electronic transport properties of germanium oligomers catenating into linear chains (linear Ge chains) have been theoretically studied using first principle methods. The conduction mechanism of a Ge chain sandwiched between gold electrodes was analyzed based on the density of states and the eigenstates of the molecule in a two-probe environment. Like that of silicon chains (Si chains), the highest occupied molecular orbital of Ge chains contains the extended ?-conjugation of Ge 4p orbitals at energy levels close to the Fermi level; this is in contrast to the electronic properties of linear carbon chains. Furthermore, the conductance of a Ge chain is expected to decrease exponentially with molecular length L. The decay constant ?, which is defined as e{sup ??L}, of a Ge chain is similar to that of a Si chain, whereas the conductance of the Ge chains is higher than that of Si chains even though the Ge–Ge bond length is longer than the Si–Si bond length.

  4. Germanium blocked impurity band infrared detectors

    SciTech Connect (OSTI)

    Rossington, C.S.; Haller, E.E.

    1988-08-01

    Germanium blocked impurity band (BIB) photoconductors have been fabricated and characterized for responsivity, dark current, and noise equivalent power. BIB photoconductors theoretically provide an extension of the spectral response, a reduction in sensitivity to cosmic radiation and a reduction in noise characteristics compared with conventional photoconductors. Silicon BIB detectors have been successfully developed by researchers at Rockwell International, which do indeed meet their theoretical potential. In the proper configuration, these same Si BIB detectors are capable of continuous detection of individual photons in the wavelength range from 0.4 to 28 ..mu..m. Until the BIB concept was developed, detection of individual photons was only possible with photomultiplier tubes which detected visible light. Due to the successes of the Si BIB detectors, it seemed natural to extend this concept to Ge detectors, which would then allow an extension of the spectral response over conventional Ge detectors from /approximately/100 ..mu..m to /approximately/200 ..mu..m. 8 refs., 2 figs.

  5. Comparison of CDMS [100] and [111] Oriented Germanium Detectors

    SciTech Connect (OSTI)

    Leman, S.W.; Hertel, S.A.; /MIT, MKI; Kim, P.; /SLAC; Cabrera, B.; /Stanford U., Phys. Dept.; Do Couto E.Silva, E.; /SLAC; Figueroa-Feliciano, E.; McCarthy, K.A.; /MIT, MKI; Resch, R.; /SLAC; Sadoulet, B.; Sundqvist, K.M.; /UC, Berkeley

    2012-09-14

    The Cryogenic Dark Matter Search (CDMS) utilizes large mass, 3-inch diameter x 1-inch thick target masses as particle detectors. The target is instrumented with both phonon and ionization sensors and comparison of energy in each channel provides event-by-event classification of electron and nuclear recoils. Fiducial volume is determined by the ability to obtain good phonon and ionization signal at a particular location. Due to electronic band structure in germanium, electron mass is described by an anisotropic tensor with heavy mass aligned along the symmetry axis defined by the [111] Miller index (L valley), resulting in large lateral component to the transport. The spatial distribution of electrons varies significantly for detectors which have their longitudinal axis orientations described by either the [100] or [111] Miller indices. Electric fields with large fringing component at high detector radius also affect the spatial distribution of electrons and holes. Both effects are studied in a 3 dimensional Monte Carlo and the impact on fiducial volume is discussed.

  6. Global High-purity Pentoxide Industry 2015 Market Research Report...

    Open Energy Info (EERE)

    on. Then it analyzed the world's main region market conditions, including the product price, profit, capacity, production, capacity utilization, supply, demand and industry...

  7. Germanium FCC structure from a colloidal crystal template

    SciTech Connect (OSTI)

    Miguez, H.; Meseguer, F.; Lopez, C.; Holgado, M.; Andreasen, G.; Mifsud, A.; Fornes, V.

    2000-05-16

    Here, the authors show a method to fabricate a macroporous structure in which the pores, essentially identical, arrange regularly in a face-centered cubic (FCC) lattice. The result is a network of air spheres in a germanium medium. This structure presents the highest dielectric contrast ({epsilon}{sub Ge}/{epsilon}{sub air} = 16) ever achieved in the optical regime in such periodic structures, which could result in important applications in photonics. The authors employ solid silica colloidal crystals (opals) as templates within which a cyclic germanium growth process is carried out. Thus, the three-dimensional periodicity of the host is inherited by the guest. Afterward, the silica is removed and a germanium opal replica is obtained.

  8. Constraints on the polarization purity of a Stokes microwave radiometer

    E-Print Network [OSTI]

    Ruf, Christopher

    Constraints on the polarization purity of a Stokes microwave radiometer Christopher S. Ruf of the third and fourth Stokes parameters of microwave thermal emission can be degraded by nonideal radiometer of microwave emission by the ocean surface identified wind direc- tion as the cause [Bespalova et al., 1982

  9. Germanium Nanowire Spin-Valve Device (DMR-0819860)

    E-Print Network [OSTI]

    Petta, Jason

    Germanium Nanowire Spin-Valve Device (DMR-0819860) E-S Liu, J. Nah, K.Varahramyan, and E. Tutuc (Univ. of Texas at Austin) Figure 1 The spin-valve device comprised of a Ge nanowire bracketed by two in direction, the spin current is suppressed (spin-valve action). An applied magnetic field By is used

  10. Axion Detection with Germanium Detectors Hannah LeTourneau

    E-Print Network [OSTI]

    Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

    of germanium detectors which will be used primarily to search for neutrinoless double beta decay, which would matter, and dark energy.[2] Neutrinoless double beta decay (0) is an energet- ically possible decay method for determining the crystal axis orientation of Ge detectors. I. BACKGROUND A. Neutrinoless Double

  11. Discovery of Gallium, Germanium, Lutetium, and Hafnium Isotopes

    E-Print Network [OSTI]

    Gross, J L

    2011-01-01

    Currently, twenty-eight gallium, thirty-one germanium, thirty-five lutetium, and thirty-six hafnium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  12. Discovery of Gallium, Germanium, Lutetium, and Hafnium Isotopes

    E-Print Network [OSTI]

    J. L. Gross; M. Thoennessen

    2011-09-28

    Currently, twenty-eight gallium, thirty-one germanium, thirty-five lutetium, and thirty-six hafnium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  13. (Data in kilograms of germanium content, unless otherwise noted) Domestic Production and Use: The value of domestic refinery production of germanium, based on the 1999

    E-Print Network [OSTI]

    of germanium increased in 1999, with slightly larger amounts brought to market by Canada and China. Output from companies supplied domestic and export markets with germanium-bearing materials generated from the mining were to be recovered from ash and flue dust generated in the burning of certain coals for power

  14. GeMini: The Next Generation Mechanically-Cooled Germanium Spectrometer

    SciTech Connect (OSTI)

    Burks, M

    2008-06-13

    The next-generation mechanically-cooled germanium spectrometer has been developed. GeMini (GErmanium MINIature spectrometer) has been designed to bring high-resolution gamma-ray spectroscopy to a range of demanding field environments. Intended applications include short-notice and surprise inspections where positive nuclide identification of radioactive materials is required. GeMini weighs 2.75 kg (6 lbs) total including the detector, cryostat, cryocooler, batteries, electronics and readout. It is very low power allowing it to operate for 10 hours on a single set of rechargeable batteries. This instrument employs technology adapted from the gamma-ray spectrometer currently flying on NASA's Mercury MESSENGER spacecraft. Specifically, infrared shielding techniques allow for a vast reduction of thermal load. This in turn allows for a smaller, lighter-weight design, well-suited for a hand-held instrument. Two working prototypes have been built and tested in the lab. The target energy resolution is 3 keV fwhm or better for 1332 keV gamma-rays. The detectors currently achieve around 4.5 keV resolution, which is slightly higher than our goal due to microphonic noise. Our present work focuses on improving the resolution through mechanical and electronic means of reducing the microphonic noise. This paper will focus on the performance of the instrument and its applicability for inspectors in the field.

  15. Alternative process for thin layer etching: Application to nitride spacer etching stopping on silicon germanium

    SciTech Connect (OSTI)

    Posseme, N., E-mail: nicolas.posseme@cea.fr; Pollet, O.; Barnola, S. [CEA-LETI-Minatec, 17 rue des martyrs, 38054 Grenoble cedex 09 (France)

    2014-08-04

    Silicon nitride spacer etching realization is considered today as one of the most challenging of the etch process for the new devices realization. For this step, the atomic etch precision to stop on silicon or silicon germanium with a perfect anisotropy (no foot formation) is required. The situation is that none of the current plasma technologies can meet all these requirements. To overcome these issues and meet the highly complex requirements imposed by device fabrication processes, we recently proposed an alternative etching process to the current plasma etch chemistries. This process is based on thin film modification by light ions implantation followed by a selective removal of the modified layer with respect to the non-modified material. In this Letter, we demonstrate the benefit of this alternative etch method in term of film damage control (silicon germanium recess obtained is less than 6?A), anisotropy (no foot formation), and its compatibility with other integration steps like epitaxial. The etch mechanisms of this approach are also addressed.

  16. Titanium and germanium lined hohlraums and halfraums as multi-keV x-ray radiators

    SciTech Connect (OSTI)

    Girard, F.; Primout, M.; Villette, B.; Stemmler, Ph.; Jacquet, L.; Babonneau, D. [CEA, DAM, DIF, F-91297 Arpajon (France); Fournier, K. B. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)

    2009-05-15

    As multi-keV x-ray radiators, hohlraums and halfraums with inner walls coated with metallic materials (called liner) have been tested for the first time with laser as the energy drive. For titanium, conversion efficiencies (CEs) are up to {approx}14% for emission into 4{pi}, integrating between 4.6 and 6.5 keV when a large diameter hohlraum is used. Germanium CE is {approx}0.8% into 4{pi} between 9 and 13 keV. The highest CEs have been obtained with a 1 ns squared pulse and phase plates giving laser absorption near 99%. These high CEs are due to long-lasting, good plasma conditions for multi-keV x-ray production maintained by plasma confinement inside the plastic cylinder and plasma collision leading to a burst of x rays at a time that depends on target size. As photon emitters at 4.7 keV, titanium-lined hohlraums are the most efficient solid targets and data are close to CEs for gas targets, which are considered as the upper limit for x-ray yields since their low density allows good laser absorption and low kinetics losses. As 10.3 keV x-ray emitters, exploded germanium foils give best results one order of magnitude more efficient than thick targets; doped aerogels and lined hohlraums give similar yields, about three times lower than those from exploded foils.

  17. Diffusion of n-type dopants in germanium

    SciTech Connect (OSTI)

    Chroneos, A.; Bracht, H.

    2014-03-15

    Germanium is being actively considered by the semiconductor community as a mainstream material for nanoelectronic applications. Germanium has advantageous materials properties; however, its dopant-defect interactions are less understood as compared to the mainstream material, silicon. The understanding of self- and dopant diffusion is essential to form well defined doped regions. Although p-type dopants such as boron exhibit limited diffusion, n-type dopants such as phosphorous, arsenic, and antimony diffuse quickly via vacancy-mediated diffusion mechanisms. In the present review, we mainly focus on the impact of intrinsic defects on the diffusion mechanisms of donor atoms and point defect engineering strategies to restrain donor atom diffusion and to enhance their electrical activation.

  18. Background reduction and sensitivity for germanium double beta decay experiments

    E-Print Network [OSTI]

    H. Gómez; S. Cebrián; J. Morales; J. A. Villar

    2007-08-29

    Germanium detectors have very good capabilities for the investigation of rare phenomena like the neutrinoless double beta decay. Rejection of the background entangling the expected signal is one primary goal in this kind of experiments. Here, the attainable background reduction in the energy region where the neutrinoless double beta decay signal of 76Ge is expected to appear has been evaluated for experiments using germanium detectors, taking into consideration different strategies like the granularity of the detector system, the segmentation of each individual germanium detector and the application of Pulse Shape Analysis techniques to discriminate signal from background events. Detection efficiency to the signal is affected by background rejection techniques, and therefore it has been estimated for each of the background rejection scenarios considered. Finally, conditions regarding crystal mass, radiopurity, exposure to cosmic rays, shielding and rejection capabilities are discussed with the aim to achieve a background level of 10-3 c keV-1 kg-1 y-1 in the region of interest, which would allow to explore neutrino effective masses around 40 meV.

  19. Metastable phases in mechanically alloyed aluminum germanium powders

    SciTech Connect (OSTI)

    Yvon, P.J.; Schwarz, R.B.

    1993-03-01

    Aluminum and germanium form a simple eutectic system with no stable intermetallic phase, and limited mutual solubility. We report the formation of a metastable rhombohedral,{gamma}{sub 1} phase by mechanically alloying aluminum and germanium powders. This phase, which appears for compositions between 20 and 50 at. % germanium, has also been observed in rapidly quenched alloys, but there is disagreement as to its composition. By measuring the heat of crystallization as a function of composition, we determined the composition of the {gamma}{sub 1} phase to be Al{sub 70}Ge{sub 30}. We also produced Al{sub 70}Ge{sub 30} by arc melting the pure elements, followed by splat-quenching at a cooling rate in the range of 10{sup 8} K s{sup {minus}1}. This method produced two metastable phases, one of which was found to be the {gamma}{sub 1} phase obtained by mechanical alloying. The other was a monoclinic phase reported earlier in the literature as {gamma}{sub 2}.

  20. Extreme argon purity in a large, non-evacuated cryostat

    SciTech Connect (OSTI)

    Tope, Terry; Adamowski, Mark; Carls, B.; Hahn, A.; Jaskierny, W.; Jostlein, H.; Kendziora, C.; Lockwitz, S.; Pahlka, B.; Plunkett, R.; Pordes, S.; Rebel, B.; Schmitt, R.; Skup, E.; Stancari, M.; Yang, T.

    2014-01-29

    Liquid Argon Time Projection Chambers (LArTPCs) show promise as scalable devices for the large detectors needed for long-baseline neutrino oscillation physics. Over the last several years at Fermilab a staged approach to developing the technology for large detectors has been developed. The TPC detectors require ultra-pure liquid argon with respect to electronegative contaminants such as oxygen and water. The tolerable electronegative contamination level may be as pure as 60 parts per trillion of oxygen. Three liquid argon cryostats operated at Fermilab have achieved the extreme purity required by TPCs. These three cryostats used evacuation to remove atmospheric contaminants as the first purification step prior to filling with liquid argon. Future physics experiments may require very large detectors with tens of kilotonnes of liquid argon mass. The capability to evacuate such large cryostats adds significant cost to the cryostat itself in addition to the cost of a large scale vacuum pumping system. This paper describes a 30 ton liquid argon cryostat at Fermilab which uses purging to remove atmospheric contaminants instead of evacuation as the first purification step. This cryostat has achieved electronegative contamination levels better than 60 parts per trillion of oxygen equivalent. The results of this liquid argon purity demonstration will strongly influence the design of future TPC cryostats.

  1. A Multi-Contact, Low Capacitance HPGe Detector for High Rate Gamma Spectroscopy

    SciTech Connect (OSTI)

    Cox, Christopher

    2014-12-04

    The detection, identification and non-destructive assay of special nuclear materials and nuclear fission by-products are critically important activities in support of nuclear non-proliferation programs. Both national and international nuclear safeguard agencies recognize that current accounting methods for spent nuclear fuel are inadequate from a safeguards perspective. Radiation detection and analysis by gamma-ray spectroscopy is a key tool in this field, but no instrument exists that can deliver the required performance (energy resolution and detection sensitivity) in the presence of very high background count rates encountered in the nuclear safeguards arena. The work of this project addresses this critical need by developing a unique gamma-ray detector based on high purity germanium that has the previously unachievable property of operating in the 1 million counts-per-second range while achieving state-of-the-art energy resolution necessary to identify and analyze the isotopes of interest. The technical approach was to design and fabricate a germanium detector with multiple segmented electrodes coupled to multi-channel high rate spectroscopy electronics. Dividing the germanium detector’s signal electrode into smaller sections offers two advantages; firstly, the energy resolution of the detector is potentially improved, and secondly, the detector is able to operate at higher count rates. The design challenges included the following; determining the optimum electrode configuration to meet the stringent energy resolution and count rate requirements; determining the electronic noise (and therefore energy resolution) of the completed system after multiple signals are recombined; designing the germanium crystal housing and vacuum cryostat; and customizing electronics to perform the signal recombination function in real time. In this phase I work, commercial off-the-shelf electrostatic modeling software was used to develop the segmented germanium crystal geometry, which underwent several iterations before an optimal electrode configuration was found. The model was tested and validated against real-world measurements with existing germanium detectors. Extensive modeling of electronic noise was conducted using established formulae, and real-world measurements were performed on candidate front-end electronic components. This initial work proved the feasibility of the design with respect to expected high count rate and energy resolution performance. Phase I also delivered the mechanical design of the detector housing and vacuum cryostat to be built in Phase II. Finally, a Monte Carlo simulation was created to show the response of the complete design to a Cs-137 source. This development presents a significant advance for nuclear safeguards instrumentation with increased speed and accuracy of detection and identification of special nuclear materials. Other significant applications are foreseen for a gamma-ray detector that delivers high energy resolution (1keV FWHM noise) at high count rate (1 Mcps), especially in the areas of physics research and materials analysis.

  2. Influence of silicon dangling bonds on germanium thermal diffusion within SiO{sub 2} glass

    SciTech Connect (OSTI)

    Barba, D.; Martin, F.; Ross, G. G. [INRS Centre for Energy, Materials and Telecommunications, 1650 Boul. Lionel-Boulet, Varennes, Québec J3X 1S2 (Canada); Cai, R. S.; Wang, Y. Q. [The Cultivation Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Demarche, J.; Terwagne, G. [LARN, Centre de Recherche en Physique de la Matière et du Rayonnement (PMR), University of Namur (FUNDP), B-5000 Namur (Belgium); Rosei, F. [INRS Centre for Energy, Materials and Telecommunications, 1650 Boul. Lionel-Boulet, Varennes, Québec J3X 1S2 (Canada); Center for Self-Assembled Chemical Structures, McGill University, Montreal, Quebec H3A 2K6 (Canada)

    2014-03-17

    We study the influence of silicon dangling bonds on germanium thermal diffusion within silicon oxide and fused silica substrates heated to high temperatures. By using scanning electron microscopy and Rutherford backscattering spectroscopy, we determine that the lower mobility of Ge found within SiO{sub 2}/Si films can be associated with the presence of unsaturated SiO{sub x} chemical bonds. Comparative measurements obtained by x-ray photoelectron spectroscopy show that 10% of silicon dangling bonds can reduce Ge desorption by 80%. Thus, the decrease of the silicon oxidation state yields a greater thermal stability of Ge inside SiO{sub 2} glass, which could enable to considerably extend the performance of Ge-based devices above 1300?K.

  3. Radiation Response of Strained Silicon-Germanium Superlattices 

    E-Print Network [OSTI]

    Martin, Michael Scott

    2011-08-08

    stream_source_info MARTIN-THESIS.pdf.txt stream_content_type text/plain stream_size 103855 Content-Encoding ISO-8859-1 stream_name MARTIN-THESIS.pdf.txt Content-Type text/plain; charset=ISO-8859-1 RADIATION RESPONSE...: Nuclear Engineering RADIATION RESPONSE OF STRAINED SILICON-GERMANIUM SUPERLATTICES A Thesis by MICHAEL SCOTT MARTIN Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER...

  4. Cryostat for Ultra-low-energy Threshold Germanium Spectrometers

    SciTech Connect (OSTI)

    Aalseth, Craig E.; Bonicalzi, Ricco; Fast, James E.; Hossbach, Todd W.; Orrell, John L.; Overman, Cory T.; VanDevender, Brent A.

    2013-04-01

    Abstract: This paper presents progress on the development of a cryostat intended to improve upon the low-energy threshold (below 0.5 keV) of p-type point contact germanium gamma-ray spectrometers. Ultra-low energy thresholds are important in the detection of low-energy nuclear recoils, an event class relevant to both dark matter direct detection and measurement of coherent neutrino-nucleus scattering. The cryostat design, including a thermal and electrical-field model, is presented. A prototype cryostat has been assembled and data acquired to evaluate its vacuum and thermal performance.

  5. Cryostat for Ultra-low-energy Threshold Germanium Spectrometers

    E-Print Network [OSTI]

    Craig E. Aalseth; Ricco M. Bonicalzi; James E. Fast; Todd W. Hossbach; John L. Orrell; Cory T. Overman; Brent A. Vandevender

    2012-10-08

    This paper presents progress on the development of a cryostat intended to improve upon the low-energy threshold (below 0.5 keV) of p-type point contact germanium gamma-ray spectrometers. Ultra-low energy thresholds are important in the detection of low-energy nuclear recoils, an event class relevant to both dark matter direct detection and measurement of coherent neutrino-nucleus scattering. The cryostat design, including a thermal and electrical-field model, is given. A prototype cryostat has been assembled and data acquired to evaluate its vacuum and thermal performance.

  6. Corrosion in Supercritical carbon Dioxide: Materials, Environmental Purity, Surface Treatments, and Flow Issues

    SciTech Connect (OSTI)

    Sridharan, Kumar; Anderson, Mark

    2013-12-10

    The supercritical CO{sub 2} Brayton cycle is gaining importance for power conversion in the Generation IV fast reactor system because of its high conversion efficiencies. When used in conjunction with a sodium fast reactor, the supercritical CO{sub 2} cycle offers additional safety advantages by eliminating potential sodium-water interactions that may occur in a steam cycle. In power conversion systems for Generation IV fast reactors, supercritical CO{sub 2} temperatures could be in the range of 30°C to 650°C, depending on the specific component in the system. Materials corrosion primarily at high temperatures will be an important issue. Therefore, the corrosion performance limits for materials at various temperatures must be established. The proposed research will have four objectives centered on addressing corrosion issues in a high-temperature supercritical CO{sub 2} environment: Task 1: Evaluation of corrosion performance of candidate alloys in high-purity supercritical CO{sub 2}: The following alloys will be tested: Ferritic-martensitic Steels NF616 and HCM12A, austenitic alloys Incoloy 800H and 347 stainless steel, and two advanced concept alloys, AFA (alumina forming austenitic) steel and MA754. Supercritical CO{sub 2} testing will be performed at 450°C, 550°C, and 650°C at a pressure of 20 MPa, in a test facility that is already in place at the proposing university. High purity CO{sub 2} (99.9998%) will be used for these tests. Task 2: Investigation of the effects of CO, H{sub 2}O, and O{sub 2} impurities in supercritical CO{sub 2} on corrosion: Impurities that will inevitably present in the CO{sub 2} will play a critical role in dictating the extent of corrosion and corrosion mechanisms. These effects must be understood to identify the level of CO{sub 2} chemistry control needed to maintain sufficient levels of purity to manage corrosion. The individual effects of important impurities CO, H{sub 2}O, and O{sub 2} will be investigated by adding them separately to high purity CO{sub 2}. Task 3: Evaluation of surface treatments on the corrosion performance of alloys in supercritical CO{sub 2}: Surface treatments can be very beneficial in improving corrosion resistance. Shot peening and yttrium and aluminum surface treatments will be investigated. Shot peening refines the surface grain sizes and promotes protective Cr-oxide layer formation. Both yttrium and aluminum form highly stable oxide layers (Y{sub 2}O{sub 3} and Al{sub 2}O{sub 3}), which can get incorporated in the growing Fe-oxide layer to form an impervious complex oxide to enhance corrosion resistance. Task 4: Study of flow-assisted corrosion of select alloys in supercritical CO{sub 2} under a selected set of test conditions: To study the effects of flow-assisted corrosion, tests will be conducted in a supercritical CO{sub 2} flow loop. An existing facility used for supercritical water flow studies at the proposing university will be modified for use in this task. The system is capable of flow velocities up to 10 m/s and can operate at temperatures and pressures of up to 650°C and 20 MPa, respectively. All above tasks will be performed in conjunction with detailed materials characterization and analysis using scanning electron microscopy/energy dispersive spectroscopy (SEM-EDS), x-ray diffraction (XRD), Auger electron spectroscopy (AES) techniques, and weight change measurements. Inlet and outlet gas compositions will be monitored using gas chromatography-mass spectrometry (GCMS).

  7. When Bacteria Get Good: Progress, Purity, and the Making of Probiotics

    E-Print Network [OSTI]

    Yates, Allison

    2013-01-01

    45 Latour (1987). When Bacteria Get Good Bickler, S. W. , J.When Bacteria GetGood WHEN BACTERIA GET GOOD Progress, Purity, and the Making

  8. Biogenic opal germanium/silicon ratios used to monitor upwelling intensity in Newport Lagoon section, Monterey Formation, California

    SciTech Connect (OSTI)

    Murnane, R.J.

    1986-04-01

    Empirical evidence and modeling of geochemical cycles of silicon (Si) and germanium (Ge) suggest that opal Ge/Si ratios record water Ge/Si ratios although some fractionation of germanium from silicon occurs during biogenic opal formation. Modeling results also suggest that opal Ge/Si ratios could record changes in upwelling intensity. In today's oceans, areas of high productivity associated with upwelling show relatively elevated surface-water nutrient concentrations, whereas areas of low productivity with restricted upwelling exhibit low surface-water nutrient concentrations. Fractionation of germanium from silicon during biogenic opal formation would cause the surface ocean's Ge/Si ratio to increase as surface-water nutrient concentrations are lowered. Diatomites from the Newport Lagoon section of the Monterey Formation were analyzed to test the hypothesis that biogenic opal Ge/Si ratios could be used to trace upwelling intensity. Diatom assemblages of the Monterey Formation vary with upwelling intensity over a time scale of millions of years. Samples collected from the middle and late Miocene have high ratios (up to 8 x 10/sup -7/) when diatom assemblages indicate relatively weak upwelling, and low ratios (less than 6 x 10/sup -7/) when diatom assemblages indicate relatively strong upwelling. These ratios agree with modeling predictions. Opal Ge/Si ratios may also record upwelling fluctuations on much shorter times scales. Adjacent, centimeter-scale, lighter and darker layers record past variations in biogenic and terrigenous inputs to ocean-bottom sediments. Opal Ge/Si ratios may indicate whether the darker layers result from a relative decrease in surface-water productivity in response to a reduction in upwelling intensity, or only from a relative increase in terrigenous detrital inputs.

  9. Reduction of phosphorus diffusion in germanium by fluorine implantation

    SciTech Connect (OSTI)

    El Mubarek, H. A. W. [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom)

    2013-12-14

    The control of phosphorus (P) diffusion in germanium (Ge) is essential for the realisation of ultrashallow n-type junctions in Ge. This work reports a detailed study of the effect of fluorine (F) co-implantation on P diffusion in Ge. P and F profiles were characterized by secondary ion mass spectroscopy. The ion implantation damage was investigated using cross sectional transmission electron microscopy. It is shown that F co-implantation reduces the implanted P profile width and reduces both intrinsic and extrinsic P diffusion in Ge. A defect mediated mechanism for the strong influence of F co-implantation on P diffusion in Ge is proposed and invokes the formation of F{sub n}V{sub m} clusters in the F-amorphized Ge layer. A fraction of these F{sub n}V{sub m} clusters decorate the interstitial type end-of-range defects in the re-grown Ge layer and the rest react during re-growth with interstitial germanium atoms diffusing back from the amorphous crystalline interface. The Ge vacancies are then annihilated and mobile interstitial F is released and out diffuses from the surface. This results in a re-grown Ge layer which has a low vacancy concentration and in which the P diffusion rate is reduced. These results open the way to the realization of enhanced Ge n-type devices.

  10. Mechanically Cooled Large-Volume Germanium Detector Systems for Nuclear Explosion Monitoring

    SciTech Connect (OSTI)

    Hull, Ethan L.; Pehl, Richard H.; Lathrop, James R.; Martin, Gregory N.; Mashburn, R. B.; Miley, Harry S.; Aalseth, Craig E.; Hossbach, Todd W.; Bowyer, Ted W.

    2006-09-21

    Compact maintenance free mechanical cooling systems are being developed to operate large volume (~570 cm3, ~3 kg, 140% or larger) germanium detectors for field applications. We are using a new generation of Stirling-cycle mechanical coolers for operating the very largest volume germanium detectors with absolutely no maintenance or liquid nitrogen requirements. The user will be able to leave these systems unplugged on the shelf until needed. The flip of a switch will bring a system to life in ~1 hour for measurements. The maintenance-free operating lifetime of these detector systems will exceed five years. These features are necessary for remote long-duration liquid-nitrogen free deployment of large-volume germanium gamma-ray detector systems for Nuclear Explosion Monitoring (NEM). The Radionuclide Aerosol Sampler/Analyzer (RASA) will greatly benefit from the availability of such detectors by eliminating the need for liquid nitrogen at RASA sites while still allowing the very largest available germanium detectors to be utilized. These mechanically cooled germanium detector systems being developed here will provide the largest, most sensitive detectors possible for use with the RASA. To provide such systems, the appropriate technical fundamentals are being researched. Mechanical cooling of germanium detectors has historically been a difficult endeavor. The success or failure of mechanically cooled germanium detectors stems from three main technical issues: temperature, vacuum, and vibration. These factors affect one another. There is a particularly crucial relationship between vacuum and temperature. These factors will be experimentally studied both separately and together to insure a solid understanding of the physical limitations each factor places on a practical mechanically cooled germanium detector system for field use. Using this knowledge, a series of mechanically cooled germanium detector prototype systems are being designed and fabricated. Our collaborators at Pacific Northwest National Laboratory (PNNL) will evaluate these detector systems on the bench top and eventually in RASA systems to insure reliable and practical operation.

  11. Method of manufacturing a niobium-aluminum-germanium superconductive material

    DOE Patents [OSTI]

    Wang, John L. (San Francisco, CA); Pickus, Milton R. (Oakland, CA); Douglas, Kent E. (Redondo Beach, CA)

    1980-01-01

    A method for manufacturing flexible Nb.sub.3 (Al,Ge) multifilamentary superconductive material in which a sintered porous niobium compact is infiltrated with an aluminum-germanium alloy and thereafter deformed and heat treated in a series of steps at different successively higher temperatures preferably below 1000.degree. C. to produce filaments composed of Nb.sub.3 (Al,G3) within the compact. By avoiding temperatures in excess of 1000.degree. C. during the heat treatment, cladding material such as copper can be applied to facilitate a deformation step preceding the heat treatment and can remain in place through the heat treatment to also serve as a temperature stabilizer for supeconductive material produced. Further, these lower heat treatment temperatures favor formation of filaments with reduced grain size and, hence with more grain boundaries which in turn increase the current-carrying capacity of the superconductive material.

  12. Materials science and design for germanium monolithic light source on silicon

    E-Print Network [OSTI]

    Cai, Yan, Ph. D. Massachusetts Institute of Technology

    2014-01-01

    Germanium (Ge) is an optically active material with the advantages of Si-CMOS compatibility and monolithic integration. It has great potential to be used as the light emitter for Si photonics. Tensile strain and n-type ...

  13. Mechanically Cooled Large-Volume Germanium Detector Systems for Nuclear Explosion Monitoring DOENA27323-1

    SciTech Connect (OSTI)

    Hull, E.L.

    2006-07-28

    Compact maintenance free mechanical cooling systems are being developed to operate large volume germanium detectors for field applications. To accomplish this we are utilizing a newly available generation of Stirling-cycle mechanical coolers to operate the very largest volume germanium detectors with no maintenance. The user will be able to leave these systems unplugged on the shelf until needed. The flip of a switch will bring a system to life in ~ 1 hour for measurements. The maintenance-free operating lifetime of these detector systems will exceed 5 years. These features are necessary for remote long-duration liquid-nitrogen free deployment of large-volume germanium gamma-ray detector systems for Nuclear Explosion Monitoring. The Radionuclide Aerosol Sampler/Analyzer (RASA) will greatly benefit from the availability of such detectors by eliminating the need for liquid nitrogen at RASA sites while still allowing the very largest available germanium detectors to be reliably utilized.

  14. Experimental study of thermal conductivity reduction of silicon-germanium nanocomposite for thermoelastic application

    E-Print Network [OSTI]

    Lee, Hohyun, 1978-

    2005-01-01

    To improve the thermoelectric energy conversion efficiency of silicon germanium (SiGe), two methods were used to decrease the thermal conductivity by increasing phonon boundary scattering at interfaces. In the first method, ...

  15. Demonstration of surface electron rejection with interleaved germanium detectors for dark matter searches

    E-Print Network [OSTI]

    Anderson, Adam Jonathan

    The SuperCDMS experiment in the Soudan Underground Laboratory searches for dark matter with a 9-kg array of cryogenic germanium detectors. Symmetric sensors on opposite sides measure both charge and phonons from each ...

  16. Results from a Low-Energy Analysis of the CDMS II Germanium Data

    E-Print Network [OSTI]

    Figueroa-Feliciano, Enectali

    We report results from a reanalysis of data from the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory. Data taken between October 2006 and September 2008 using eight germanium detectors ...

  17. Electronic and magnetic properties of Fe and Mn doped two dimensional hexagonal germanium sheets

    SciTech Connect (OSTI)

    Soni, Himadri R. Jha, Prafulla K.

    2014-04-24

    Using first principles density functional theory calculations, the present paper reports systematic total energy calculations of the electronic properties such as density of states and magnetic moment of pristine and iron and manganese doped two dimensional hexagonal germanium sheets.

  18. CASCADES: An Ultra-Low-Background Germanium Crystal Array at Pacific Northwest National Laboratory

    SciTech Connect (OSTI)

    Keillor, M. E.; Aalseth, C. E.; Day, A. R.; Erikson, L. E.; Fast, J. E.; Glasgow, B. D.; Hoppe, E. W.; Hossbach, T. W.; Hyronimus, B. J.; Miley, H. S.; Myers, A. W.; Seifert, A.; Stavenger, T. J. [Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States)

    2011-12-13

    State-of-the-art treaty verification techniques, environmental surveillance, and physics experiments require increased sensitivity for detecting and quantifying radionuclides of interest. This can be accomplished with new detector designs that establish high detection efficiency and reduced instrument backgrounds. Current research is producing an intrinsic germanium (HPGe) array designed for high detection efficiency, ultra-low-background performance, and sensitive {gamma}--{gamma} coincidence detection. The system design is optimized to accommodate filter paper samples, e.g. samples collected by the Radionuclide Aerosol Sampler/Analyzer. The system will provide high sensitivity for weak collections on atmospheric filter samples (e.g.<10{sup 5} fissions) as well as offering the potential to gather additional information from higher activity filters using gamma cascade coincidence detection. The first of two HPGe crystal arrays in ultra-low-background vacuum cryostats has been assembled, with the second in progress. Traditional methods for constructing ultra-low-background detectors were followed, including use of materials known to be low in radioactive contaminants, use of ultra-pure reagents, and clean room assembly. The cryostat is constructed mainly from copper electroformed into near-final geometry at Pacific Northwest National Laboratory. Details of the detector assembly and initial background and spectroscopic measurement results are presented; also a description of the custom analysis package used by this project is given.

  19. CASCADES: An Ultra-Low-Background Germanium Crystal Array at Pacific Northwest National Laboratory

    SciTech Connect (OSTI)

    Keillor, Martin E.; Aalseth, Craig E.; Day, Anthony R.; Erikson, Luke E.; Fast, James E.; Glasgow, Brian D.; Hoppe, Eric W.; Hossbach, Todd W.; Hyronimus, Brian J.; Miley, Harry S.; Myers, Allan W.; Seifert, Allen; Stavenger, Timothy J.

    2011-07-14

    State-of-the-art treaty verification techniques, environmental surveillance, and physics experiments require increased sensitivity for detecting and quantifying radionuclides of interest. This can be accomplished with new detector designs that establish high detection efficiency and reduced instrument backgrounds. Current research is producing an intrinsic germanium (HPGe) array designed for high detection efficiency, ultra-low-background performance, and sensitive {gamma}-{gamma} coincidence detection. The system design is optimized to accommodate filter paper samples, e.g., samples collected by the Radionuclide Aerosol Sampler/Analyzer. The system will provide high sensitivity for weak collections on atmospheric filter samples (e.g., < 10{sup 5} fissions), as well as offering the potential to gather additional information from higher activity filters using gamma cascade coincidence detection. The first of two HPGe crystal arrays in ultra-low-background vacuum cryostats has been assembled, with the second in progress. Traditional methods for constructing ultra-low-background detectors were followed, including use of materials known to be low in radioactive contaminants, use of ultra-pure reagents, and clean room assembly. The cryostat is constructed mainly from copper electroformed into near-final geometry at Pacific Northwest National Laboratory. Details of the detector assembly and initial background and spectroscopic measurement results are presented; also a description of the custom analysis package used by this project is given.

  20. Germanium-rich silicon-germanium materials for field-effect modular application

    E-Print Network [OSTI]

    Jongthammanurak, Samerkhae

    2008-01-01

    The development of electric-field-induced optical modulation in the materials capable of monolithically integrated on silicon (Si) substrates offer the possibility of high-speed modulation in a pico second timeframe as ...

  1. Gas Purity effect on GEM Performance in He and Ne at Low Temperatures

    E-Print Network [OSTI]

    Galea, R; Dodd, J; Ju, Y; Leltchouk, M; Pavlyuchenko, D; Rehak, P; Tcherniatine, V; Willis, W

    2006-01-01

    The performance of Gas Electron Multipliers (GEMs) in gaseous He, Ne, He+H2 and Ne+H2 was studied at temperatures in the range of 3-293 K. This paper reports on previously published measurements and additional studies on the effects of the purity of the gases in which the GEM performance is evaluated. In He, at temperatures between 77 and 293 K, triple-GEM structures operate at rather high gains, exceeding 1000. There is an indication that this high gain is achieved through the Penning effect as a result of impurities in the gas. At lower temperatures the gain-voltage characteristics are significantly modified probably due to the freeze-out of these impurities. Double-GEM and single-GEM structures can operate down to 3 K at gains reaching only several tens at a gas density of about 0.5 g/l; at higher densities the maximum gain drops further. In Ne, the maximum gain also drops at cryogenic temperatures. The gain drop in Ne at low temperatures can be re-established in Penning mixtures of Ne+H2: very high gains,...

  2. Influence of Electronic Type Purity on the Lithiation of Single-Walled Carbon Nanotubes

    SciTech Connect (OSTI)

    Jaber-Ansari, Laila; Iddir, Hakim; Curtiss, Larry A.; Hersam, Mark C.

    2014-03-25

    Single-walled carbon nanotubes (SWCNTs) have emerged as one of the leading additives for high-capacity nanocomposite lithium ion battery electrodes due to their ability to improve electrode conductivity, current collection efficiency, and charge/discharge rate for high power applications. However, since as-grown SWCNTs possess a distribution of physical and electronic structures, it is of high interest to determine which subpopulations of SWCNTs possess the highest lithiation capacity and to develop processing methods that can enhance the lithiation capacity of underperforming SWCNT species. Toward this end, SWCNT electronic type purity is controlled via density gradient ultracentrifugation, enabling a systematic study of the lithiation of SWCNTs as a function of metal versus semiconducting content. Experimentally, vacuum-filtered freestanding films of metallic SWCNTs are found to accommodate lithium with an order of magnitude higher capacity than their semiconducting counterparts, which is consistent with ab initio molecular dynamics and density functional theory calculations in the limit of isolated SWCNTs. In contrast, SWCNT film densification leads to the enhancement of the lithiation capacity of semiconducting SWCNTs to levels comparable to metallic SWCNTs, which is corroborated by theoretical calculations that show increased lithiation of semiconducting SWCNTs in the limit of small SWCNT*SWCNT spacing. Overall, these results will inform ongoing efforts to utilize SWCNTs as conductive additives in nanocomposite lithium ion battery electrodes.

  3. Temperature dependence of ion-beam mixing in crystalline and amorphous germanium isotope multilayer structures

    SciTech Connect (OSTI)

    Radek, M.; Bracht, H., E-mail: bracht@uni-muenster.de [Institute of Materials Physics, Westfälische Wilhelms-Universität Münster, 48149 Münster (Germany); Posselt, M.; Liedke, B.; Schmidt, B. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, D-01328 Dresden (Germany); Bougeard, D. [Institut für Experimentelle und Angewandte Physik, 93040 Regensburg (Germany)

    2014-01-14

    Self-atom mixing induced by 310 keV gallium (Ga) ion implantation in crystalline and preamorphized germanium (Ge) at temperatures between 164 K and 623 K and a dose of 1?×?10{sup 15}?cm{sup ?2} is investigated using isotopic multilayer structures of alternating {sup 70}Ge and {sup nat}Ge layers grown by molecular beam epitaxy. The distribution of the implanted Ga atoms and the ion-beam induced depth-dependent self-atom mixing was determined by means of secondary ion mass spectrometry. Three different temperature regimes of self-atom mixing, i.e., low-, intermediate-, and high-temperature regimes are observed. At temperatures up to 423 K, the mixing is independent of the initial structure, whereas at 523?K, the intermixing of the preamorphized Ge structure is about twice as high as that of crystalline Ge. At 623?K, the intermixing of the initially amorphous Ge structure is strongly reduced and approaches the mixing of the crystalline material. The temperature dependence of ion-beam mixing is described by competitive amorphization and recrystallization processes.

  4. Low energy consumption method for separating gaseous mixtures and in particular for medium purity oxygen production

    DOE Patents [OSTI]

    Jujasz, Albert J. (North Olmsted, OH); Burkhart, James A. (Olmsted Falls, OH); Greenberg, Ralph (New York, NY)

    1988-01-01

    A method for the separation of gaseous mixtures such as air and for producing medium purity oxygen, comprising compressing the gaseous mixture in a first compressor to about 3.9-4.1 atmospheres pressure, passing said compressed gaseous mixture in heat exchange relationship with sub-ambient temperature gaseous nitrogen, dividing the cooled, pressurized gaseous mixture into first and second streams, introducing the first stream into the high pressure chamber of a double rectification column, separating the gaseous mixture in the rectification column into a liquid oxygen-enriched stream and a gaseous nitrogen stream and supplying the gaseous nitrogen stream for cooling the compressed gaseous mixture, removing the liquid oxygen-enriched stream from the low pressure chamber of the rectification column and pumping the liquid, oxygen-enriched steam to a predetermined pressure, cooling the second stream, condensing the cooled second stream and evaporating the oxygen-enriched stream in an evaporator-condenser, delivering the condensed second stream to the high pressure chamber of the rectification column, and heating the oxygen-enriched stream and blending the oxygen-enriched stream with a compressed blend-air stream to the desired oxygen concentration.

  5. High density-high purity graphite prepared by hot isostatic pressing in refractory metal containers

    DOE Patents [OSTI]

    Hoenig, Clarence L. (Livermore, CA)

    1994-01-01

    Porous graphite in solid form is hot isostatically pressed in a refractory metal container to produce a solid graphite monolith with a bulk density greater than or equal to 2.10 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed, chemically vapor deposited, or coated by some other suitable means onto graphite. Hot isostatic pressing at 2200.degree. C. and 30 KSI (206.8 MPa) argon pressure for two hours produces a bulk density of 2.10 g/cc. Complex shapes can be made.

  6. High density-high purity graphite prepared by hot isostatic pressing in refractory metal containers

    DOE Patents [OSTI]

    Hoenig, C.L.

    1994-08-09

    Porous graphite in solid form is hot isostatically pressed in a refractory metal container to produce a solid graphite monolith with a bulk density greater than or equal to 2.10 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed, chemically vapor deposited, or coated by some other suitable means onto graphite. Hot isostatic pressing at 2,200 C and 30 KSI (206.8 MPa) argon pressure for two hours produces a bulk density of 2.10 g/cc. Complex shapes can be made. 1 fig.

  7. Hydrometallurgical recovery of germanium from coal gasification fly ash: pilot plant scale evaluation

    SciTech Connect (OSTI)

    Arroyo, F.; Fernandez-Pereira, C.; Olivares, J.; Coca, P. [University of Seville, Seville (Spain)

    2009-04-15

    In this article, a hydrometallurgical method for the selective recovery of germanium from fly ash (FA) has been tested at pilot plant scale. The pilot plant flowsheet comprised a first stage of water leaching of FA, and a subsequent selective recovery of the germanium from the leachate by solvent extraction method. The solvent extraction method was based on Ge complexation with catechol in an aqueous solution followed by the extraction of the Ge-catechol complex (Ge(C{sub 6}H{sub 4}O{sub 2}){sub 3}{sup 2-}) with an extracting organic reagent (trioctylamine) diluted in an organic solvent (kerosene), followed by the subsequent stripping of the organic extract. The process has been tested on a FA generated in an integrated gasification with combined cycle (IGCC) process. The paper describes the designed 5 kg/h pilot plant and the tests performed on it. Under the operational conditions tested, approximately 50% of germanium could be recovered from FA after a water extraction at room temperature. Regarding the solvent extraction method, the best operational conditions for obtaining a concentrated germanium-bearing solution practically free of impurities were as follows: extraction time equal to 20 min; aqueous phase/organic phase volumetric ratio equal to 5; stripping with 1 M NaOH, stripping time equal to 30 min, and stripping phase/organic phase volumetric ratio equal to 5. 95% of germanium were recovered from water leachates using those conditions.

  8. The Fuel Accident Condition Simulator (FACS) furnace system for high temperature performance testing of VHTR fuel

    SciTech Connect (OSTI)

    Paul A. Demkowicz; David V. Laug; Dawn M. Scates; Edward L. Reber; Lyle G. Roybal; John B. Walter; Jason M. Harp; Robert N. Morris

    2012-10-01

    The AGR-1 irradiation of TRISO-coated particle fuel specimens was recently completed and represents the most successful such irradiation in US history, reaching peak burnups of greater than 19% FIMA with zero failures out of 300,000 particles. An extensive post-irradiation examination (PIE) campaign will be conducted on the AGR-1 fuel in order to characterize the irradiated fuel properties, assess the in-pile fuel performance in terms of coating integrity and fission metals release, and determine the fission product retention behavior during high temperature safety testing. A new furnace system has been designed, built, and tested to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000 degrees C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, and Eu), iodine, and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator furnace system and the associated fission gas monitoring system, as well as preliminary system calibration results.

  9. GERDA, a GERmanium Detector Array for the search for neutrinoless {beta}{beta} decay in 76Ge

    SciTech Connect (OSTI)

    Pandola, L.; Tomei, C. [INFN, Laboratori Nazionali del Gran Sasso, S.S. 17 bis km 18.910, 67010 Assergi (AQ) (Italy)

    2006-07-11

    The GERDA project, searching for neutrinoless double beta-decay of 76Ge with enriched germanium detectors submerged in a cryogenic bath, has been approved for installation at the Gran Sasso National Laboratory (LNGS), Italy. The GERDA technique is aiming at a dramatic reduction of the background due to radioactive contaminations of the materials surrounding the detectors. This will lead to a sensitivity of about 1026 years on the half-life of neutrinoless double beta decay. Already in the first phase of the experiment, GERDA will be able to investigate with high statistical significance the claimed evidence for neutrinoless double beta decay of 76Ge based on the data of the Heidelberg-Moscow experiment.

  10. The MAJORANA DEMONSTRATOR: A Search for Neutrinoless Double-beta Decay of Germanium-76

    E-Print Network [OSTI]

    MAJORANA Collaboration; A. G. Schubert; E. Aguayo; F. T. Avignone III; H. O. Back; A. S. Barabash; M. Bergevin; F. E. Bertrand; M. Boswell; V. Brudanin; M. Busch; Y-D. Chan; C. D. Christofferson; J. I. Collar; D. C. Combs; R. J. Cooper; J. A. Detwiler; J. Leon; P. J. Doe; Yu. Efremenko; V. Egorov; H. Ejiri; S. R. Elliott; J. Esterline; J. E. Fast; N. Fields; P. Finnerty; F. M. Fraenkle; V. M. Gehman; G. K. Giovanetti; M. P. Green; V. E. Guiseppe; K. Gusey; A. L. Hallin; R. Hazama; R. Henning; A. Hime; E. W. Hoppe; M. Horton; S. Howard; M. A. Howe; R. A. Johnson; K. J. Keeter; M. E. Keillor; C. Keller; J. D. Kephart; M. F. Kidd; A. Knecht; O. Kochetov; S. I. Konovalov; R. T. Kouzes; B. LaFerriere; B. H. LaRoque; L. E. Leviner; J. C. Loach; S. MacMullin; M. G. Marino; R. D. Martin; D. -M. Mei; J. Merriman; M. L. Miller; L. Mizouni; M. Nomachi; J. L. Orrell; N. Overman; D. G. Phillips II; A. W. P. Poon; G. Perumpilly; G. Prior; D. C. Radford; K. Rielage; R. G. H. Robertson; M. C. Ronquest; T. Shima; M. Shirchenko; K. J. Snavely; V. Sobolev; D. Steele; J. Strain; K. Thomas; V. Timkin; W. Tornow; I. Vanyushin; R. L. Varner; K. Vetter; K. Vorren; J. F. Wilkerson; B. A. Wolfe; E. Yakushev; A. R. Young; C. ?H. Yu; V. Yumatov; C. Zhan

    2011-09-07

    The observation of neutrinoless double-beta decay would determine whether the neutrino is a Majorana particle and provide information on the absolute scale of neutrino mass. The MAJORANA Collaboration is constructing the DEMONSTRATOR, an array of germanium detectors, to search for neutrinoless double-beta decay of 76-Ge. The DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76-Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment. Operation of the DEMONSTRATOR aims to determine whether a future tonne-scale germanium experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76-Ge neutrinoless double-beta decay Q-value of 2039 keV.

  11. The MAJORANA DEMONSTRATOR: A Search for Neutrinoless Double-beta Decay of Germanium-76

    SciTech Connect (OSTI)

    Schubert, Alexis G.; Aguayo, Estanislao; Avignone, F. T.; Zhang, C.; Back, Henning O.; Barabash, Alexander S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Collar, J. I.; Combs, Dustin C.; Cooper, R. J.; Detwiler, Jason A.; Leon, Jonathan D.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Esterline, James H.; Fast, James E.; Fields, N.; Finnerty, P.; Fraenkle, Florian; Gehman, Victor M.; Giovanetti, G. K.; Green, M.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Horton, Mark; Howard, Stanley; Howe, Mark; Johnson, R. A.; Keeter, K.; Keillor, Martin E.; Keller, C.; Kephart, Jeremy D.; Kidd, M. F.; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaFerriere, Brian D.; LaRoque, B. H.; Leviner, L.; Loach, J. C.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Mei, Dong-Ming; Merriman, Jason H.; Miller, M. L.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; Overman, Nicole R.; Phillips, D.; Poon, Alan; Perumpilly, Gopakumar; Prior, Gersende; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Sobolev, V.; Steele, David; Strain, J.; Thomas, K.; Timkin, V.; Tornow, Werner; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Vorren, Kris R.; Wilkerson, J. F.; Wolfe, B. A.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2012-09-28

    The observation of neutrinoless double-beta decay would determine whether the neutrino is a Majorana particle and provide information on the absolute scale of neutrino mass. The MAJORANA Collaboration is constructing the DEMONSTRATOR, an array of germanium detectors, to search for neutrinoless double-beta decay of 76Ge. The DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment. Operation of the DEMONSTRATOR aims to determine whether a future tonne-scale germanium experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge neutrinoless double-beta decay Q-value of 2039 keV.

  12. Structural and optoelectronic properties of germanium-rich islands grown on silicon using molecular beam epitaxy

    SciTech Connect (OSTI)

    Nataraj, L.; Sustersic, N.; Coppinger, M.; Gerlein, L. F.; Kolodzey, J. [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States); Cloutier, S. G. [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States); Delaware Biotechnology Institute, University of Delaware, Newark, Delaware 19711 (United States)

    2010-03-22

    We report on the structural and optoelectronic properties of self-assembled germanium-rich islands grown on silicon using molecular beam epitaxy. Raman, photocurrent, photoluminescence, and transient optical spectroscopy measurements suggest significant built-in strains and a well-defined interface with little intermixing between the islands and the silicon. The shape of these islands depends on the growth conditions and includes pyramid, dome, barn-shaped, and superdome islands. Most importantly, we demonstrate that these germanium-rich islands provide efficient light emission at telecommunication wavelengths on a complementary metal-oxide semiconductor-compatible platform.

  13. Doping of germanium and silicon crystals with non-hydrogenic acceptors for far infrared lasers

    DOE Patents [OSTI]

    Haller, Eugene E. (Berkeley, CA); Brundermann, Erik (Berlin, DE)

    2000-01-01

    A method for doping semiconductors used for far infrared lasers with non-hydrogenic acceptors having binding energies larger than the energy of the laser photons. Doping of germanium or silicon crystals with beryllium, zinc or copper. A far infrared laser comprising germanium crystals doped with double or triple acceptor dopants permitting the doped laser to be tuned continuously from 1 to 4 terahertz and to operate in continuous mode. A method for operating semiconductor hole population inversion lasers with a closed cycle refrigerator.

  14. Optimization of the Transport Shield for Neutrinoless Double Beta-decay Enriched Germanium

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.; Reid, Douglas J.; Fast, James E.

    2012-04-15

    This document presents results of an investigation of the material and geometry choice for the transport shield of germanium, the active detector material used in 76Ge neutrinoless double beta decay searches. The objective of this work is to select the optimal material and geometry to minimize cosmogenic production of radioactive isotopes in the germanium material. The design of such a shield is based on the calculation of the cosmogenic production rate of isotopes that are known to cause interfering backgrounds in 76Ge neutrinoless double beta decay searches.

  15. A study of helium-3 activation applied to the determination of oxygen in germanium 

    E-Print Network [OSTI]

    Francis, Georgann

    1972-01-01

    as lanthanum fluoride. A detection lim1t of one part-per-mill1on is given. Aleksandrova, et al. have developed a chem1cal 17 separation procedure f or 1solating fluorine-18 from germanium 1rradiated. with helium-) particles. Azsenic, selenium..., and germanium radioisotopes are removed by prec1pitation, and fluorine-18 is 1solated for counting by steam d1stillation and precip1tat1on of lanthanum fluoride, Exper1mental results pub- lished 1ndicate determ1nations for a few parts-per- b1llion oxygen 1n...

  16. Quantum-State Purity of Heralded Single Photons Produced from Frequency-Anti-Correlated Biphotons

    E-Print Network [OSTI]

    Shengwang Du

    2015-07-13

    We analyze the quantum-state purity of heralded single photons produced from frequency-anti-correlated biphotons. We find that the quantum-state purity in time-frequency domain depends strongly on the response time uncertainty of the trigger-photon detector that heralds the generation of its paired photon. If the trigger response time is much shorter than the two-photon coherence time, the time-frequency quantum-state purity of heralded single photons approaches unity and the heralded single photon is in a nearly pure state. If the trigger response time is much longer than the two-photon coherence time, the heralded photon is then projected onto a mixed state. Making use of the time-frequency entanglement, heralded single photons with a well-defined temporal wave function or a frequency superposition state can be produced and engineered. This time-frequency entanglement allows for shaping heralded single photons through nonlocal spectral modulation.

  17. Analysis of a small sample geometry for concurrent identification and quantification of mixed-nuclide samples 

    E-Print Network [OSTI]

    Krieger, Kenneth Vincent

    1999-01-01

    sample, each emitting a different type of radiation. High purity germanium detectors (HPGe) and liquid scintillation counters (LSC) can be used to quantify activities of several known sources. This can be done without buying more or expensive equipment...

  18. GERMANIUM--2002 32.1 References that include a section mark () are found in the Internet

    E-Print Network [OSTI]

    Group of Eagle-Picher Technologies, LLC (EPT) in Quapaw, OK, remained the largest domestic producer in September 2001. The company continues to produce germanium-rich residues as a byproduct of processing zinc catalyst for polyethylene terephthalate (PET), a commercially important plastic; in infrared night vision

  19. Method and apparatus for measuring purity of noble gases

    DOE Patents [OSTI]

    Austin, Robert (Largo, FL)

    2008-04-01

    A device for detecting impurities in a noble gas includes a detection chamber and a source of pulsed ultraviolet light. The pulse of the ultraviolet light is transferred into the detection chamber and onto a photocathode, thereby emitting a cloud of free electrons into the noble gas within the detection chamber. The cloud of electrons is attracted to the opposite end of the detection chamber by a high positive voltage potential at that end and focused onto a sensing anode. If there are impurities in the noble gas, some or all of the electrons within the cloud will bond with the impurity molecules and not reach the sensing anode. Therefore, measuring a lower signal at the sensing anode indicates a higher level of impurities while sensing a higher signal indicates fewer impurities. Impurities in the range of one part per billion can be measured by this device.

  20. Evaluating the purity of a {sup 57}Co flood source by PET

    SciTech Connect (OSTI)

    DiFilippo, Frank P., E-mail: difilif@ccf.org [Department of Nuclear Medicine, Cleveland Clinic, Cleveland, Ohio 44195 (United States)

    2014-11-01

    Purpose: Flood sources of {sup 57}Co are commonly used for quality control of gamma cameras. Flood uniformity may be affected by the contaminants {sup 56}Co and {sup 58}Co, which emit higher energy photons. Although vendors specify a maximum combined {sup 56}Co and {sup 58}Co activity, a convenient test for flood source purity that is feasible in a clinical environment would be desirable. Methods: Both {sup 56}Co and {sup 58}Co emit positrons with branching 19.6% and 14.9%, respectively. As is known from {sup 90}Y imaging, a positron emission tomography (PET) scanner is capable of quantitatively imaging very weak positron emission in a high single-photon background. To evaluate this approach, two {sup 57}Co flood sources were scanned with a clinical PET/CT multiple times over a period of months. The {sup 56}Co and {sup 58}Co activity was clearly visible in the reconstructed PET images. Total impurity activity was quantified from the PET images after background subtraction of prompt gamma coincidences. Results: Time-of-flight PET reconstruction was highly beneficial for accurate image quantification. Repeated measurements of the positron-emitting impurities showed excellent agreement with an exponential decay model. For both flood sources studied, the fit parameters indicated a zero intercept and a decay half-life consistent with a mixture of {sup 56}Co and {sup 58}Co. The total impurity activity at the reference date was estimated to be 0.06% and 0.07% for the two sources, which was consistent with the vendor’s specification of <0.12%. Conclusions: The robustness of the repeated measurements and a thorough analysis of the detector corrections and physics suggest that the accuracy is acceptable and that the technique is feasible. Further work is needed to validate the accuracy of this technique with a calibrated high resolution gamma spectrometer as a gold standard, which was not available for this study, and for other PET detector models.

  1. Design of an Online Fission Gas Monitoring System for Post-irradiation Examination Heating Tests of Coated Fuel Particles for High-Temperature Gas-Cooled Reactors

    SciTech Connect (OSTI)

    Dawn Scates

    2010-10-01

    A new Fission Gas Monitoring System (FGMS) has been designed at the Idaho National Laboratory (INL) for use of monitoring online fission gas-released during fuel heating tests. The FGMS will be used with the Fuel Accident Condition Simulator (FACS) at the Hot Fuels Examination Facility (HFEF) located at the Materials and Fuels Complex (MFC) within the INL campus. Preselected Advanced Gas Reactor (AGR) TRISO (Tri-isotropic) fuel compacts will undergo testing to assess the fission product retention characteristics under high temperature accident conditions. The FACS furnace will heat the fuel to temperatures up to 2,000ºC in a helium atmosphere. Released fission products such as Kr and Xe isotopes will be transported downstream to the FGMS where they will accumulate in cryogenically cooledcollection traps and monitored with High Purity Germanium (HPGe) detectors during the heating process. Special INL developed software will be used to monitor the accumulated fission products and will report data in near real-time. These data will then be reported in a form that can be readily available to the INL reporting database. This paper describes the details of the FGMS design, the control and acqusition software, system calibration, and the expected performance of the FGMS. Preliminary online data may be available for presentation at the High Temperature Reactor (HTR) conference.

  2. Anomalous small angle x-ray scattering studies of amorphous metal-germanium alloys

    SciTech Connect (OSTI)

    Rice, M.

    1993-12-01

    This dissertation addresses the issue of composition modulation in sputtered amorphous metal-germanium thin films with the aim of understanding the intermediate range structure of these films as a function of composition. The investigative tool used in this work is anomalous small-angle X-ray scattering (ASAXS). The primary focus of this investigation is the amorphous iron-germanium (a-Fe{sub x}Ge{sub 100-x}) system with particular emphasis on the semiconductor-rich regime. Brief excursions are made into the amorphous tungsten-germanium (a-W{sub x}Ge{sub 100-x}) and the amorphous molybdenum-germanium (a-Mo{sub x}Ge{sub 100-x}) systems. All three systems exhibit an amorphous structure over a broad composition range extending from pure amorphous germanium to approximately 70 atomic percent metal when prepared as sputtered films. Across this composition range the structures change from the open, covalently bonded, tetrahedral network of pure a-Ge to densely packed metals. The structural changes are accompanied by a semiconductor-metal transition in all three systems as well as a ferromagnetic transition in the a-Fe{sub x}Ge{sub 100-x} system and a superconducting transition in the a-Mo{sub x}Ge{sub 100-x} system. A long standing question, particularly in the a-Fe{sub x}Ge{sub 100-x} and the a-Mo{sub x}Ge{sub 100-x} systems, has been whether the structural changes (and therefore the accompanying electrical and magnetic transitions) are accomplished by homogeneous alloy formation or phase separation. The application of ASAXS to this problem proves unambiguously that fine scale composition modulations, as distinct from the simple density fluctuations that arise from cracks and voids, are present in the a-Fe{sub x}Ge{sub 100-x}, a-W{sub x}Ge{sub 100-x}, and a-Mo{sub x}Ge{sub 100-x} systems in the semiconductor-metal transition region. Furthermore, ASAXS shows that germanium is distributed uniformly throughout each sample in the x<25 regime of all three systems.

  3. Investigations of segregation phenomena in highly strained Mn-doped Ge wetting layers and Ge quantum dots embedded in silicon

    SciTech Connect (OSTI)

    Prestat, E., E-mail: eric.prestat@gmail.com; Porret, C.; Favre-Nicolin, V.; Tainoff, D.; Boukhari, M.; Bayle-Guillemaud, P.; Jamet, M.; Barski, A., E-mail: andre.barski@cea.com [INAC, SP2M, CEA and Université Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble (France)

    2014-03-10

    In this Letter, we investigate manganese diffusion and the formation of Mn precipitates in highly strained, few monolayer thick, Mn-doped Ge wetting layers and nanometric size Ge quantum dot heterostructures embedded in silicon. We show that in this Ge(Mn)/Si system manganese always precipitates and that the size and the position of Mn clusters (precipitates) depend on the growth temperature. At high growth temperature, manganese strongly diffuses from germanium to silicon, whereas decreasing the growth temperature reduces the manganese diffusion. In the germanium quantum dots layers, Mn precipitates are detected, not only in partially relaxed quantum dots but also in fully strained germanium wetting layers between the dots.

  4. 4{\\pi}{\\beta} (LS)-{\\gamma} (HPGe) Digital Coincidence System Based on Synchronous High-Speed Multichannel Data Acquisition

    E-Print Network [OSTI]

    Chen, Jifeng; Liang, Juncheng; Liu, Jiacheng

    2015-01-01

    A dedicated 4{\\pi}{\\beta} (LS)-{\\gamma} (HPGe)digital coincidence system has been developed in this work, which includes five acquisition channels. Three analog-to-digital converter (ADC) acquisition channels with an acquisition resolution of 8 bits and acquisition rate of 1GSPS (sample per second) are utilized to collect the signals from three Photo multiplier tubes (PMTs) which are adopted to detect {\\beta} decay, and two acquisition channels with an acquisition resolution of 16 bits and acquisition rate of 50MSPS are utilized to collect the signals from high-purity germanium (HPGe) which are adopted to detect {\\gamma} decay. In order to increase the accuracy of the coincidence system, all the five acquisition channels are synchronous within 500ps. The data collected by the five acquisition channels will be transmitted to the host PC through PCI bus and saved as a file. Off-line software is applied for the 4{\\pi}{\\beta} (LS)-{\\gamma} (HPGe) coincidence and data analysis as needed in practical application. W...

  5. Recommendations for a Static Cosmic Ray Shield for Enriched Germanium Detectors

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Orrell, John L.; Ankney, Austin S.; Berguson, Timothy J.

    2011-09-21

    This document provides a detailed study of cost and materials that could be used to shield the detector material of the international Tonne-scale germanium neutrinoless double-beta decay experiment from hadronic particles from cosmic ray showers at the Earth's surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during storage; in particular, when the detector material is being worked on at the detector manufacturer's facility. This work considers two options for shielding the detector material from cosmic ray particles. One option is to use a pre-existing structure already located near the detector manufacturer, such as Canberra Industries in Meriden, Connecticut. The other option is to build a shield onsite at a detector manufacturer's site. This paper presents a cost and efficiency analysis of such construction.

  6. Nanorods of Silicon and Germanium with Well-Defined Shapes and Sizes

    SciTech Connect (OSTI)

    Slavi C. Sevov

    2012-05-03

    We have made number of important discoveries along the major goals of the project, namely i) electrodeposition of germanium thin films from clusters, ii) synthesis of cluster-based surfactants with long hydrocarbon chains and micelles made of them, iii) grafting of Ge{sub 9}-clusters onto self assembled films of siloxanes attached to glass substrates, iv) doping of Ge{sub 9}-clusters, and v) expanding the clusters to ten-atom cages of Ge{sub 10}{sup 2-}.

  7. HYDROGEN EFFECTS ON THE CHARACTER OF DISLOCATIONS IN HIGH-PURITY ALUMINUM

    E-Print Network [OSTI]

    Ferreira, Paulo J.

    . ROBERTSON{ and H. K. BIRNBAUM Department of Materials Science and Engineering and Frederick Seitz Materials nucleating and growing a brittle hydride phase [29]; and hydrogen reducing the stacking-fault energy [20, 24

  8. Summary Report of Summer Work: High Purity Single Crystal Growth & Microstructure of Ferritic-Martensitic Steels

    SciTech Connect (OSTI)

    Pestovich, Kimberly Shay

    2015-08-18

    Harnessing the power of the nuclear sciences for national security and to benefit others is one of Los Alamos National Laboratory’s missions. MST-8 focuses on manipulating and studying how the structure, processing, properties, and performance of materials interact at the atomic level under nuclear conditions. Within this group, single crystal scintillators contribute to the safety and reliability of weapons, provide global security safeguards, and build on scientific principles that carry over to medical fields for cancer detection. Improved cladding materials made of ferritic-martensitic alloys support the mission of DOE-NE’s Fuel Cycle Research and Development program to close the nuclear fuel cycle, aiming to solve nuclear waste management challenges and thereby increase the performance and safety of current and future reactors.

  9. Preparation and Characterization of High Purity Cobalt (III) Tetrasulfonatophenyl Porphyrin Chloride

    E-Print Network [OSTI]

    Collins, Gary S.

    ) 1180 (s) -SO3 - 3 1122 (s) 1125 (s) -SO3 - 3 1035 (s) 1037 (s) Phenyl3 1009 (s) 1004 (s) (C-N)/(CC)3

  10. The Importance of Domain Size and Purity in High-Efficiency Organic...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to be separated into electrons (purple dots) and holes (green dots). Organic photovoltaics are of great interest as a potential source of renewable and economically viable...

  11. OpenEI Community - Global High-purity Pentoxide Industry 2015 Market

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo, Maryland:NPI VenturesNewSt.Information OlindaOnslow County,OpTICOpenBarter Jump

  12. The Importance of Domain Size and Purity in High-Efficiency Organic Solar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired Solar FuelTechnologyTel: Name: Rm.mountains"

  13. The Importance of Domain Size and Purity in High-Efficiency Organic Solar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired Solar FuelTechnologyTel: Name: Rm.mountains"Cells The

  14. The Importance of Domain Size and Purity in High-Efficiency Organic Solar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired Solar FuelTechnologyTel: Name: Rm.mountains"Cells

  15. Global High-purity Pentoxide Industry 2015 Market Research Report | OpenEI

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View New Pages RecentPlant <SilverChangeInformationGlobal

  16. The Importance of Domain Size and Purity in High-Efficiency Organic Solar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S.Week Day Year(active tab)FrustratedThe Higgs:

  17. The Importance of Domain Size and Purity in High-Efficiency Organic Solar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S.Week Day Year(active tab)FrustratedThe Higgs:Cells The

  18. The Importance of Domain Size and Purity in High-Efficiency Organic Solar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S.Week Day Year(active tab)FrustratedThe Higgs:Cells

  19. The Importance of Domain Size and Purity in High-Efficiency Organic Solar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S.Week Day Year(active tab)FrustratedThe

  20. The Importance of Domain Size and Purity in High-Efficiency Organic Solar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S.Week Day Year(active tab)FrustratedTheCells The

  1. Metastable phases in the aluminum-germanium alloy system: Synthesis by mechanical alloying and pressure induced transformations

    SciTech Connect (OSTI)

    Yvon, P.

    1994-01-01

    Al and Ge form a simple equilibrium eutectic with limited mutual solubility and no intermetallic intermediate phases. We used a regular solution approach to model effects of pressure on Al-Ge. Effects of pressure are to extend solubility of Ge in Al, to displace the eutectic composition towards the Ge rich side, and to slightly decrease the eutectic temperature. We designed thermobaric treatments to induce crystal-to-glass transformations in fine grain mixtures of Al and Ge. We used Merrill-Bassett diamond anvil cells to perform experiments at high pressures. We built an x-ray apparatus to determine the structure of alloys at pressure and from cryogenic temperatures to 400C. Two-phase Al-Ge samples with fine microstructures were prepared by splat-quenching and mechanical alloying. We observed a crystal-to-glass transformation at about 80 kbar. The amorphous phase formed was metastable at ambient temperature after pressure release. This was confirmed by TEM. The amorphous phase obtained by pressurization was found to have a liquid-like structure and was metallic. In the TEM samples we also observed the presence of a second amorphous phase formed upon release of the pressure. This second phase had a tetrahedrally-bonded continuous random network structure, similar to that of semi-conducting amorphous germanium.

  2. Improved fill factors in amorphous silicon solar cells on zinc oxide by insertion of a germanium layer to block impurity incorporation

    E-Print Network [OSTI]

    Improved fill factors in amorphous silicon solar cells on zinc oxide by insertion of a germanium 80401 (Received 22 September 2003; accepted 25 May 2004) Amorphous silicon based solar cells deposited of a thin, amorphous germanium layer at the ZnO­p-layer interface improves the cell performance and diode

  3. The MAJORANA DEMONSTRATOR: An R&D project towards a tonne-scale germanium neutrinoless double-beta decay search

    E-Print Network [OSTI]

    Reyco Henning; for the MAJORANA Collaboration

    2009-07-09

    The MAJORANA collaboration is pursuing the development of the so-called MAJORANA DEMONSTRATOR. The DEMONSTRATOR is intended to perform research and development towards a tonne-scale germanium-based experiment to search for the neutrinoless double-beta decay of Ge-76. The DEMONSTRATOR can also perform a competitive direct dark matter search for light WIMPs in the 1-10 GeV/c^2 mass range. It will consist of approximately 60-kg of germanium detectors in an ultra-low background shield located deep underground at the Sanford Underground Laboratory in Lead, SD. The DEMONSTRATOR will also perform background and technology studies, and half of the detector mass will be enriched germanium. This talk will review the motivation, design, technology and status of the DEMONSTRATOR.

  4. The MAJORANA DEMONSTRATOR: An R and D project towards a tonne-scale germanium neutrinoless double-beta decay search

    SciTech Connect (OSTI)

    Aalseth, C. E.; Ely, J.; Fast, J. E.; Fuller, E.; Hoppe, E. W.; Keillor, M.; Kouzes, R. T.; Miley, H. S.; Orrell, J. L.; Thompson, R.; Warner, R. [Pacific Northwest National Laboratory, Richland, WA (United States); Amman, M.; Bergevin, M.; Chan, Y.-D.; Detwiler, J. A.; Fujikawa, B.; Loach, J. C.; Luke, P. N.; Poon, A. W. P; Prior, G. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)] (and others)

    2009-12-17

    The MAJORANA collaboration is pursuing the development of the so-called MAJORANA DEMONSTRATOR. The DEMONSTRATOR is intended to perform research and development towards a tonne-scale germanium-based experiment to search for the neutrinoless double-beta decay of {sup 76}Ge. The DEMONSTRATOR can also perform a competitive direct dark matter search for light WIMPs in the 1-10 GeV/c{sup 2} mass range. It will consist of approximately 60 kg of germanium detectors in an ultra-low background shield located deep underground at the Sanford Underground Laboratory in Lead, SD. The DEMONSTRATOR will also perform background and technology studies, and half of the detector mass will be enriched germanium. This talk will review the motivation, design, technology and status of the Demonstrator.

  5. The MAJORANA DEMONSTRATOR: An R&D project towards a tonne-scale germanium neutrinoless double-beta decay search

    SciTech Connect (OSTI)

    Aalseth, Craig E.; Amman, M.; Amsbaugh, John F.; Avignone, F. T.; Back, Henning O.; Barabash, A.; Barbeau, Phil; Beene, Jim; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Bugg, William; Burritt, Tom H.; Chan, Yuen-Dat; Collar, J. I.; Cooper, R. J.; Creswick, R.; Detwiler, Jason A.; Doe, P. J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, Steven R.; Ely, James H.; Esterline, James H.; Farach, H. A.; Fast, James E.; Fields, N.; Finnerty, P.; Fujikawa, Brian; Fuller, Erin S.; Gehman, Victor; Giovanetti, G. K.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Hossbach, Todd W.; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keillor, Martin E.; Keller, C.; Kephart, Jeremy D.; Kidd, Mary; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Lesko, Kevin; Leviner, L.; Loach, J. C.; Luke, P.; MacMullin, S.; Marino, Michael G.; Mei, Dong-Ming; Miley, Harry S.; Miller, M.; Mizouni, Leila K.; Montoya, A.; Myers, A. W.; Nomachi, Masaharu; Odom, Brian; Orrell, John L.; Phillips, D.; Poon, Alan; Prior, Gersende; Qian, J.; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Rodriguez, Larry; Rykaczewski, Krzysztof P.; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Strain, J.; Thomas, K.; Thompson, Robert C.; Timkin, V.; Tornow, W.; Van Wechel, T. D.; Vanyushin, I.; Vetter, Kai; Warner, Ray A.; Wilkerson, J.; Wouters, Jan; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C. L.; Zimmerman, S.

    2009-12-17

    The MAJORANA collaboration is pursuing the development of the so-called MAJORANA DEMONSTRATOR. The DEMONSTRATOR is intended to perform research and development towards a tonne-scale germanium-based experiment to search for the neutrinoless double-beta decay of 76Ge. The DEMONSTRATOR can also perform a competitive direct dark matter search for light WIMPs in the 1?10GeV/c2 mass range. It will consist of approximately 60 kg. of germanium detectors in an ultra-low background shield located deep underground at the Sanford Underground Laboratory in Lead, SD. The DEMONSTRATOR will also perform background and technology studies, and half of the detector mass will be enriched germanium. This talk will review the motivation, design, technology and status of the Demonstrator.

  6. Experimental Search for Solar Axions via Coherent Primakoff Conversion in a Germanium Spectrometer

    E-Print Network [OSTI]

    Avignone, F T; Brodzinski, R; Collar, J I; Creswick, R J; Di Gregorio, D E; Farach, H A; Gattone, A O; Guérard, C K; Hasenbalg, F; Huck, H; Miley, H S; Morales, A; Morales, J; Nussinov, S; De Solorzano, A O; Reeves, J H; Villar, J; Zioutas, Konstantin

    1998-01-01

    Results are reported of an experimental search for the unique, rapidly varying temporal pattern of solar axions coherently converting into photons via the Primakoff effect in a single crystal germanium detector. This conversion is predicted when axions are incident at a Bragg angle with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1 kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of $g_{a\\gamma \\gamma} < 2.7\\cdot 10^{-9}$ GeV$^{-1}$, independent of axion mass up to ~ 1 keV.

  7. Next-Generation Germanium Spectrometer Background Reduction Techniques at 2 MeV

    SciTech Connect (OSTI)

    Brodzinski, Ronald L.

    2005-04-01

    The Majorana project, a next-generation 76Ge neutrinoless double-beta decay experiment being undertaken by a large international collaboration, has the goal of measuring the neutrinoless double-beta decay rate by observing monochromatic events at 2039 keV in 500 kg of isotopically enriched 76Ge gamma-ray spectrometers. In order to achieve the desired sensitivity limit, the background in the 2037-2041 keV region must be reduced to <1 event per year in the entire germanium array. The effects of various background reduction techniques, and the combination thereof, to produce a huge 76Ge spectrometer array with virtually zero background are discussed.

  8. In operandi observation of dynamic annealing: A case study of boron in germanium nanowire devices

    SciTech Connect (OSTI)

    Kole?nik-Gray, Maria M.; Krsti?, Vojislav; Sorger, Christian; Weber, Heiko B.; Biswas, Subhajit; Holmes, Justin D.

    2015-06-08

    We report on the implantation of boron in individual, electrically contacted germanium nanowires with varying diameter and present a technique that monitors the electrical properties of a single device during implantation of ions. This method gives improved access to study the dynamic annealing ability of the nanowire at room temperature promoted by its quasi-one-dimensional confinement. Based on electrical data, we find that the dopant activation efficiency is nontrivially diameter dependent. As the diameter decreases, a transition from a pronounced dynamic-annealing to a radiation-damage dominated regime is observed.

  9. Ultra-Low-Energy Germanium Detector for Neutrino-Nucleus Coherent Scattering and Dark Matter Searches

    E-Print Network [OSTI]

    Henry T. Wong

    2008-03-01

    The status and plans of a research program on the development of ultra-low-energy germanium detectors with sub-keV sensitivities are reported. We survey the scientific goals which include the observation of neutrino-nucleus coherent scattering, the studies of neutrino magnetic moments, as well as the searches of WIMP dark matter. In particular, a threshold of 100-200 eV and a sub-keV background comparable to underground experiments were achieved with prototype detectors. New limits were set for WIMPs with mass between 3-6 GeV. The prospects of the realization of full-scale experiments are discussed.

  10. Germanium films by polymer-assisted deposition (Patent) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) |productionPatent:CompressionSciTechwithin the vadose zoneGermanium

  11. Holey Germanium - New Routes to Ordered Nanoporous Semiconductors

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHigh energyHighland View school4-TP59.01vacuum vessel |

  12. Observations of the intense and ultra-long burst GRB041219a with the Germanium Spectrometer on INTEGRAL

    E-Print Network [OSTI]

    S. McBreen; L. Hanlon; S. McGlynn; B. McBreen; S. Foley; R. Preece; A. von Kienlin; O. R. Williams

    2006-08-23

    GRB041219a is the brightest burst localised by INTEGRAL. The intense burst occurred about ~250s after the precursor and the long delay enabled optical and near infrared telescopes to observe the prompt emission. We present comprehensive results of the temporal and spectral analyses, including line and afterglow searches using the spectrometer, SPI, aboard INTEGRAL, BAT on Swift and ASM on RXTE. We avail of multi-wavelength data to generate broadband spectra of GRB041219a and afterglow. Spectra for the burst and sub-intervals were fit by the Band model and also by the quasithermal model. The high resolution Germanium spectrometer data were searched for emission and absorption features and for gamma-ray afterglow. The overall burst and sub-intervals are well fit by the Band model. The photon index below the break energy shows a marked change after the quiescent time interval. In addition the spectra are well described by a black body component with a power law. The burst was detected by BAT and ASM during the long quiescent interval in SPI indicating the central engine might not be dormant but that the emission occurs in different bands. No significant emission or absorption features were found and limits of 900 eV and 120 eV are set on the most significant features. No gamma-ray afterglow was detected from the end of the prompt phase to ~12 hours post-burst. Broadband spectra of the prompt emission were generated in 7 time intervals using gamma-ray, x-ray, optical and near-infrared data and these were compared to the high-redshift burst GRB050904. The optical and gamma-ray emission are correlated in GRB041219a. The spectral lag was determined using data from the BAT and it changes throughout the burst. A number of pseudo-redshifts were evaluated and large dispersion in values was found.

  13. Dynamical behavior of the entanglement, purity and energy between atomic qubits in motion under the influence of thermal environment

    E-Print Network [OSTI]

    L. Tan; Y. Q. Zhang; Z. H. Zhu; L. W. Liu

    2010-05-20

    The entanglement, purity and energy of two isolated two-level atoms which are initially prepared in Bell state and each interacts with a thermal cavity field are investigated by considering the atomic motion and the field-mode structure. We achieve the analytical solutions of the atomic qubits by using the algebraic dynamical approach and the influences of the field-mode structure parameter, the strength of the thermal field and the detuning on the entanglement, purity and energy are discussed. We also investigate the state evolution of the atomic qubits based on the entanglement-purity-energy diagrams. Our results show that the disentanglement process of the atomic qubits accompanies by excitations transferring from atomic subsystem to cavity field modes and atomic state from a pure state convert to the mixed states.

  14. A Search for Neutrinoless Double-beta Decay of Germanium-76 J.F. Wilkerson1, 2, 3

    E-Print Network [OSTI]

    A Search for Neutrinoless Double-beta Decay of Germanium-76 J.F. Wilkerson1, 2, 3 and S.R. Elliott4, The Majorana collaboration[1] is searching for neutrinoless double beta decay using 76 Ge, which has previously of neutrinoless double-beta decay would show that lepton number is violated, neutrinos are Majorana particles

  15. Simulation of the deflection of 200- and 450-GeV protons by a bent germanium crystal

    SciTech Connect (OSTI)

    Koshcheev, V. P. Kholodov, A. K.; Morgun, D. A.

    2009-04-15

    It is shown that the result obtained by numerically solving the kinetic Fokker-Planck equation in the transverse-energy space on the basis of computer simulations of channeled-particle trajectories describes well the results of an experiment that studied the deflection of 200- and 450-GeV protons by a bent germanium crystal.

  16. PHYSICAL REVIEW B 85, 045202 (2012) Electron spin-phonon interaction symmetries and tunable spin relaxation in silicon and germanium

    E-Print Network [OSTI]

    Flatte, Michael E.

    2012-01-01

    .25.Rb, 72.10.Di I. INTRODUCTION The favorable material properties of silicon have permitted with direct-gap semiconductors, the valley degeneracy of silicon and germanium opens up new channels for spin semiconductor devices,1­3 in which spins of electronic carriers are manipu- lated instead of a charge current

  17. Free-standing AlxGa1-xAs heterostructures by gas-phase etching of germanium

    E-Print Network [OSTI]

    Free-standing AlxGa1-xAs heterostructures by gas-phase etching of germanium Garrett D. Cole,1,a Yu; published online 28 June 2010 We outline a facile fabrication technique for the realization of free-standing technique for the realization of free-standing films for a diverse suite of applications. By propagating

  18. Highly Conductive Germanium Nanowires Made by a Simple, One-Step...

    Office of Science (SC) Website

    in semiconductor technology. It is also an attractive anode material for lithium-ion batteries because it has a large theoretical charge-discharge capacity compared to...

  19. Stabilization techniques and silicon-germanium saturable absorbers for high repetition rate mode-locked lasers

    E-Print Network [OSTI]

    Grawert, Felix Jan

    2005-01-01

    The monolithic integration of passively mode-locked solid-state lasers at highest repetition rates has been prevented by Q-switching instabilities and the lack of integrable saturable absorbers to date. In this thesis we ...

  20. Impact of Salt Purity on Interfacial Water Organization Revealed by Conventional and Heterodyne-Detected Vibrational Sum Frequency

    E-Print Network [OSTI]

    Impact of Salt Purity on Interfacial Water Organization Revealed by Conventional and Heterodyne of the chosen salts and their solutions. This is true not only for the ACS grade salts but also vibrational sum frequency generation (VSFG) and heterodyne-detected VSFG (HD-VSFG) spectroscopy that salt

  1. Atomic-scale characterization of germanium isotopic multilayers by atom probe tomography

    SciTech Connect (OSTI)

    Shimizu, Y.; Takamizawa, H.; Toyama, T.; Inoue, K.; Nagai, Y. [Oarai Center, Institute for Materials Research, Tohoku University, 2145-2 Narita, Oarai, Ibaraki 311-1313 (Japan); Kawamura, Y.; Uematsu, M.; Itoh, K. M. [School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Haller, E. E. [University of California at Berkeley and Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

    2013-01-14

    We report comparison of the interfacial sharpness characterization of germanium (Ge) isotopic multilayers between laser-assisted atom probe tomography (APT) and secondary ion mass spectrometry (SIMS). An alternating stack of 8-nm-thick naturally available Ge layers and 8-nm-thick isotopically enriched {sup 70}Ge layers was prepared on a Ge(100) substrate by molecular beam epitaxy. The APT mass spectra consist of clearly resolved peaks of five stable Ge isotopes ({sup 70}Ge, {sup 72}Ge, {sup 73}Ge, {sup 74}Ge, and {sup 76}Ge). The degree of intermixing at the interfaces between adjacent layers was determined by APT to be around 0.8 {+-} 0.1 nm which was much sharper than that obtained by SIMS.

  2. Constraints on Millicharged Neutrinos via Atomic Ionizations with Germanium Detectors at sub-keV Sensitivities

    E-Print Network [OSTI]

    Chen, Jiunn-Wei; Li, Hau-Bin; Liu, C -P; Singh, Lakhwinder; Wong, Henry T; Wu, Chih-Liang; Wu, Chih-Pan

    2014-01-01

    With the advent of detectors with sub-keV sensitivities, atomic ionization has been identified as a promising avenue to probe possible neutrino electromagnetic properties. The interaction cross-sections induced by millicharged neutrinos are evaluated with the ab-initio multi-configuration relativistic random-phase approximation. There is significant enhancement at atomic binding energies compared to that when the electrons are taken as free particles. Positive signals would distinctly manifest as peaks at specific energies with known intensity ratios. Selected reactor neutrino data with germanium detectors at analysis threshold as low as 300 eV are studied. No such signatures are observed, and a combined limit on the neutrino charge fraction of $| \

  3. A Segmented, Enriched N-type Germanium Detector for Neutrinoless Double Beta-Decay Experiments

    SciTech Connect (OSTI)

    Leviner, L.; Aalseth, Craig E.; Ahmed, M. W.; Avignone, F. T.; Back, Henning O.; Barabash, Alexander S.; Boswell, M.; De Braeckeleer, L.; Brudanin, V.; Chan, Yuen-Dat; Egorov, Viatcheslav; Elliott, Steven R.; Gehman, Victor M.; Hossbach, Todd W.; Kephart, Jeremy; Kidd, M. F.; Konovalov, S.; Lesko, Kevin; Li, Jingyi; Mei, Dongming; Mikhailov, S.; Miley, Harry S.; Radford, D. C.; Reeves, James H.; Sandukovsky, Viatcheslav; Umatov, Valdimir; Underwood, T. A.; Tornow, W.; Wu, Y. K.; Young, A.

    2014-01-21

    We present data characterizing the performance of the _rst segmented, N- type Ge detector, isotopically enriched to 85% 76Ge. This detector, based on the Ortec PT6x2 design and referred to as SEGA (Segmented, Enriched Germanium Assembly), was developed as a possible prototype for neutrinoless double beta-decay measurements by the Majorana collaboration. We present some of the general characteristics (including bias potential, efficiency, leakage current, and integral cross-talk) for this detector in its temporary cryostat. We also present an analysis of the resolution of the detector, and demonstrate that for all but two segments there is at least one channel that reaches the Majorana resolution goal below 4 keV FWHM at 2039 keV, and all channels are below 4.5 keV FWHM.

  4. Method using laser irradiation for the production of atomically clean crystalline silicon and germanium surfaces

    DOE Patents [OSTI]

    Ownby, Gary W. (Knoxville, TN); White, Clark W. (Oak Ridge, TN); Zehner, David M. (Lenoir City, TN)

    1981-01-01

    This invention relates to a new method for removing surface impurities from crystalline silicon or germanium articles, such as off-the-shelf p- or n-type wafers to be doped for use as junction devices. The principal contaminants on such wafers are oxygen and carbon. The new method comprises laser-irradiating the contaminated surface in a non-reactive atmosphere, using one or more of Q-switched laser pulses whose parameters are selected to effect melting of the surface without substantial vaporization thereof. In a typical application, a plurality of pulses is used to convert a surface region of an off-the-shelf silicon wafer to an automatically clean region. This can be accomplished in a system at a pressure below 10.sup.-8 Torr, using Q-switched ruby-laser pulses having an energy density in the range of from about 60 to 190 MW/cm.sup.2.

  5. Pulse Shape Analysis with a Broad-Energy Germanium Detector for the GERDA experiment

    E-Print Network [OSTI]

    Dušan Budjáš; Marik Barnabé Heider; Oleg Chkvorets; Stefan Schönert; Nikita Khanbekov

    2008-12-09

    To reduce background in experiments looking for rare events, such as the GERDA double beta decay experiment, it is necessary to employ active background-suppression techniques. One of such techniques is the pulse shape analysis of signals induced by the interaction of radiation with the detector. Analysis of the time-development of the impulses can distinguish between an interaction of an electron and an interaction of a multiple-scattered photon inside the detector. This information can be used to eliminate background events from the recorded data. Results of pulse-shape analysis of signals from a commercially available broad-energy germanium detector are presented and the pulse-shape discrimination capability of such detector configuration for use in low-background experiments is discussed.

  6. Prospects of cold dark matter searches with an ultra-low-energy germanium detector

    E-Print Network [OSTI]

    H. T. Wong

    2007-11-08

    The report describes the research program on the development of ultra-low-energy germanium detectors, with emphasis on WIMP dark matter searches. A threshold of 100 eV is achieved with a 20 g detector array, providing a unique probe to the low-mas WIMP. Present data at a surface laboratory is expected to give rise to comparable sensitivities with the existing limits at the $\\rm{5 - 10 GeV}$ WIMP-mass range. The projected parameter space to be probed with a full-scale, kilogram mass-range experiment is presented. Such a detector would also allow the studies of neutrino-nucleus coherent scattering and neutrino magnetic moments.

  7. Improved WIMP-search reach of the CDMS II germanium data

    E-Print Network [OSTI]

    R. Agnese; A. J. Anderson; M. Asai; D. Balakishiyeva; D. Barker; R. Basu Thakur; D. A. Bauer; J. Billard; A. Borgland; M. A. Bowles; D. Brandt; P. L. Brink; R. Bunker; B. Cabrera; D. O. Caldwell; R. Calkins; D. G. Cerdeño; H. Chagani; Y. Chen; J. Cooley; B. Cornell; C. H. Crewdson; P. Cushman; M. Daal; P. C. F. Di Stefano; T. Doughty; L. Esteban; S. Fallows; E. Figueroa-Feliciano; G. L. Godfrey; S. R. Golwala; J. Hall; H. R. Harris; S. A. Hertel; T. Hofer; D. Holmgren; L. Hsu; M. E. Huber; D. Jardin; A. Jastram; O. Kamaev; B. Kara; M. H. Kelsey; A. Kennedy; M. Kiveni; K. Koch; A. Leder; B. Loer; E. Lopez Asamar; P. Lukens; R. Mahapatra; V. Mandic; K. A. McCarthy; N. Mirabolfathi; R. A. Moffatt; S. M. Oser; K. Page; W. A. Page; R. Partridge; M. Pepin; A. Phipps; K. Prasad; M. Pyle; H. Qiu; W. Rau; P. Redl; A. Reisetter; Y. Ricci; H. E. Rogers; T. Saab; B. Sadoulet; J. Sander; K. Schneck; R. W. Schnee; S. Scorza; B. Serfass; B. Shank; D. Speller; D. Toback; S. Upadhyayula; A. N. Villano; B. Welliver; J. S. Wilson; D. H. Wright; X. Yang; S. Yellin; J. J. Yen; B. A. Young; J. Zhang

    2015-04-22

    CDMS II data from the 5-tower runs at the Soudan Underground Laboratory were reprocessed with an improved charge-pulse fitting algorithm. Two new analysis techniques to reject surface-event backgrounds were applied to the 612 kg days germanium-detector WIMP-search exposure. An extended analysis was also completed by decreasing the 10 keV analysis threshold to $\\sim$5 keV, to increase sensitivity near a WIMP mass of 8 GeV/$c^2$. After unblinding, there were zero candidate events above a deposited energy of 10 keV and 6 events in the lower-threshold analysis. This yielded minimum WIMP-nucleon spin-independent scattering cross-section limits of $1.8 \\times 10^{-44}$ and $1.18 \\times 10 ^{-41}$ cm$^2$ at 90\\% confidence for 60 and 8.6 GeV/$c^2$ WIMPs, respectively. This improves the previous CDMS II result by a factor of 2.4 (2.7) for 60 (8.6) GeV/$c^2$ WIMPs.

  8. Influence of germanium nano-inclusions on the thermoelectric power factor of bulk bismuth telluride alloy

    SciTech Connect (OSTI)

    Satyala, Nikhil; Zamanipour, Zahra; Norouzzadeh, Payam; Krasinski, Jerzy S.; Vashaee, Daryoosh, E-mail: daryoosh.vashaee@okstate.edu [School of Electrical and Computer Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, Oklahoma 74106 (United States); Tahmasbi Rad, Armin [School of Material Science and Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, Oklahoma 74106 (United States); Tayebi, Lobat, E-mail: daryoosh.vashaee@okstate.edu [School of Chemical Engineering, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

    2014-05-28

    Nanocomposite thermoelectric compound of bismuth telluride (Bi{sub 2}Te{sub 3}) with 5 at. % germanium nano-inclusions was prepared via mechanically alloying and sintering techniques. The influence of Ge nano-inclusions and long duration annealing on the thermoelectric properties of nanostructured Bi{sub 2}Te{sub 3} were investigated. It was found that annealing has significant effect on the carrier concentration, Seebeck coefficient, and the power factor of the thermoelectric compound. The systematic heat treatment also reduced the density of donor type defects thereby decreasing the electron concentration. While the as-pressed nanocomposite materials showed n-type properties, it was observed that with the increase of annealing time, the nanocomposite gradually transformed to an abundantly hole-dominated (p-type) sample. The long duration annealing (?500 h) resulted in a significantly enhanced electrical conductivity pertaining to the augmentation in the density and the structural properties of the sample. Therefore, a simultaneous enhancement in both electrical and Seebeck coefficient characteristics resulted in a remarkable increase in the thermoelectric power factor.

  9. A SPRAY REACTOR CONCEPT FOR CATALYTIC OXIDATION OF P-XYLENE TO PRODUCE HIGH-PURITY TEREPHTHALIC ACID

    E-Print Network [OSTI]

    Li, Meng

    2013-08-31

    Terephthalic acid (TPA), with current annual world capacity of exceeding 50 million metric tons, is a commercially important chemical used primarily in the manufacture of polyesters. A spray reactor in which the liquid phase, containing dissolved p...

  10. Foundations for quantitative microstructural models to track evolution of the metallurgical state during high purity Nb cavity fabrication

    SciTech Connect (OSTI)

    Bieler, Thomas R; Wright, Neil T; Compton, Chris C

    2014-03-15

    The goal of the Materials Science SRF Cavity Group of Michigan State University and the National Superconducting Cyclotron has been (and continues to be) to understand quantitatively the effects of process history on functional properties. These relationships were assessed via studies on Nb samples and cavity parts, which had various combinations of forming processes, welding, heat treatments, and surface preparation. A primary focus was on large-grain cavity building strategies. Effects of processing operations and exposure to hydrogen on the thermal conductivity has been identified in single and bi-crystal samples, showing that the thermal conductivity can be altered by a factor of 5 depending on process history. Characterization of single crystal tensile samples show a strong effect of crystal orientation on deformation resistance and shape changes. Large grain half cells were examined to characterize defect content and surface damage effects, which provided quantitative information about the depth damage layers from forming.

  11. Total plastic strain and electrical resistivity in high purity aluminum cyclically strained at 4.2 K 

    E-Print Network [OSTI]

    Gehan, James Terence

    1988-01-01

    important implications to the electrical behavior of aluminum reported here. B. Conce ts of Strain Controlled Tests The following section is a description of one type of mechanical test used to investigate fatigue characteristics in materials. While other... Stress 72 73 76 78 79 LIST OF TABLES Ta. ble Page I. Stopping Points and Parameter Settings of the Mechanical Test . 39 II. Test Variables of Experiments III. Rate of Mechanical Cycling and Average Number of Data Points Collected by Computer...

  12. Calcium looping process for high purity hydrogen production integrated with capture of carbon dioxide, sulfur and halides

    DOE Patents [OSTI]

    Ramkumar, Shwetha; Fan, Liang-Shih

    2013-07-30

    A process for producing hydrogen comprising the steps of: (i) gasifying a fuel into a raw synthesis gas comprising CO, hydrogen, steam, sulfur and halide contaminants in the form of H.sub.2S, COS, and HX, wherein X is a halide; (ii) passing the raw synthesis gas through a water gas shift reactor (WGSR) into which CaO and steam are injected, the CaO reacting with the shifted gas to remove CO.sub.2, sulfur and halides in a solid-phase calcium-containing product comprising CaCO.sub.3, CaS and CaX.sub.2; (iii) separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and (iv) regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO.sub.2, in the presence of synthesis gas, in the presence of H.sub.2 and O.sub.2, under partial vacuum, and combinations thereof.

  13. Absolute x-ray yields from laser-irradiated germanium-doped low-density aerogels

    SciTech Connect (OSTI)

    Fournier, K. B.; Satcher, J. H.; May, M. J.; Poco, J. F.; Sorce, C. M.; Colvin, J. D.; Hansen, S. B.; MacLaren, S. A.; Moon, S. J.; Davis, J. F. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Girard, F.; Villette, B.; Primout, M.; Babonneau, D. [Commissariat a l'Energie Atomique-Direction des Application Militaires (CEA/DAM), Ile-de-France, F91297 Arpajon (France); Coverdale, C. A.; Beutler, D. E. [Sandia National Laboratory, Albuquerque, New Mexico 87185 (United States)

    2009-05-15

    The x-ray yields from laser-irradiated germanium-doped ultra-low-density aerogel plasmas have been measured in the energy range from sub-keV to {approx_equal}15 keV at the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The targets' x-ray yields have been studied for variation in target size, aerogel density, laser pulse length, and laser intensity. For targets that result in plasmas with electron densities in the range of {approx_equal}10% of the critical density for 3{omega} light, one can expect 10-11 J/sr of x rays with energies above 9 keV, and 600-800 J/sr for energies below 3.5 keV. In addition to the x-ray spectral yields, the x-ray temporal waveforms have been measured and it is observed that the emitted x rays generally follow the delivered laser power, with late-time enhancements of emitted x-ray power correlated with hydrodynamic compression of the hot plasma. Further, the laser energy reflected from the target by plasma instabilities is found to be 2%-7% of the incident energy for individual beam intensities {approx_equal}10{sup 14}-10{sup 15} W/cm{sup 2}. The propagation of the laser heating in the target volume has been characterized with two-dimensional imaging. Source-region heating is seen to be correlated with the temporal profile of the emitted x-ray power.

  14. Direct Evidence for Abrupt Postcrystallization Germanium Precipitation in Thin Phase-Change Films of Sb-15 at. % Ge

    SciTech Connect (OSTI)

    Cabral,C.; Krusin-Elbaum, L.; Bruley, J.; Raoux, S.; Deline, V.; Madan, A.; Pinto, T.

    2008-01-01

    We present evidence for the instability in the crystalline (metallic) state of binary Te-free phase-change Ge-Sb thin films considered for integration into nonvolatile nanosized memory cells. We find that while the amorphous (semiconducting) phase of eutectic Sb-15 at. % Ge is very robust until Sb crystallization at 240 C, at about 350 C, germanium rapidly precipitates out. Ge precipitation, visualized directly with transmission electron microscopy, is exothermic and is found to affect the films' reflectivity, resistance, and stress. It converts melting into a two-step process, which may seriously impact the switching reliability of a device.

  15. High Accuracy U-235 Enrichment Verification Station for Low Enriched Uranium Alloys

    SciTech Connect (OSTI)

    Lillard, C. R.; Hayward, J. P.; Williamson, M. R.

    2012-06-07

    The Y-12 National Security Complex is playing a role in the U.S. High Performance Research Reactor (USHPRR) Conversion program sponsored by the U.S. National Nuclear Security Administration's Office of Global Threat Reduction. The USHPRR program has a goal of converting remaining U.S. reactors that continue to use highly enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. The USHPRR program is currently developing a LEU Uranium-Molybdenum (U-Mo) monolithic fuel for use in the U.S. high performance research reactors.Y-12 is supporting both the fuel development and fuel fabrication efforts by fabricating low enriched U-Mo foils from its own source material for irradiation experiments and for optimizing the fabrication process in support of scaling up the process to a commercial production scale. Once the new fuel is qualified, Y-12 will produce and ship U-Mo coupons with verified 19.75% +0.2% - 0.3% U-235 enrichment to be fabricated into fuel elements for the USHPRRs. Considering this small enrichment tolerance and the transition into HEU being set strictly at 20% U-235, a characterization system with a measurement uncertainty of less than or equal to 0.1% in enrichment is desired to support customer requirements and minimize production costs. Typical uncertainty for most available characterization systems today is approximately 1-5%; therefore, a specialized system must be developed which results in a reduced measurement uncertainty. A potential system using a High-Purity Germanium (HPGe) detector has been procured, and tests have been conducted to verify its capabilities with regards to the requirements. Using four U-Mo enrichment standards fabricated with complete isotopic and chemical characterization, infinite thickness and peak-ratio enrichment measurement methods have been considered for use. As a result of inhomogeneity within the U-Mo samples, FRAM, an isotopic analysis software, has been selected for initial testing. A systematic approach towards observing effects on FRAM's enrichment analysis has been conducted with regards to count and dead time.

  16. Correlation Between Optical Properties And Chemical Composition Of Sputter-deposited Germanium Cxide (GeOx) Films

    SciTech Connect (OSTI)

    Murphy, Neil R.; Grant, J. T.; Sun, L.; Jones, J. G.; Jakubiak, R.; Shutthanandan, V.; Ramana, Chintalapalle V.

    2014-03-18

    Germanium oxide (GeOx) films were grown on (1 0 0) Si substrates by reactive Direct-Current (DC) magnetron sputter-deposition using an elemental Ge target. The effects of oxygen gas fraction, ? = O2/(Ar + O2), on the deposition rate, structure, chemical composition and optical properties of GeOx films have been investigated. The chemistry of the films exhibits an evolution from pure Ge to mixed Ge + GeO + GeO2 and then finally to GeO2 upon increasing ? from 0.00 to 1.00. Grazing incidence X-ray analysis indicates that the GeOx films grown were amorphous. The optical properties probed by spectroscopic ellipsometry indicate that the effect of ? is significant on the optical constants of the GeOx films. The measured index of refraction (n) at a wavelength (?) of 550 nm is 4.67 for films grown without any oxygen, indicating behavior characteristic of semiconducting Ge. The transition from germanium to mixed Ge + GeO + GeO2 composition is associated with a characteristic decrease in n (? = 550 nm) to 2.62 and occurs at ? = 0.25. Finally n drops to 1.60 for ? = 0.50–1.00, where the films become GeO2. A detailed correlation between ?, n, k and stoichiometry in DC sputtered GeOx films is presented and discussed.

  17. Discrimination of Chiral Adsorption Configurations: Styrene on Germanium(100) Yun Jeong Hwang, Eunkyung Hwang, Do Hwan Kim,,, Ansoon Kim,,| Suklyun Hong,*,

    E-Print Network [OSTI]

    Kim, Sehun

    Discrimination of Chiral Adsorption Configurations: Styrene on Germanium(100) Yun Jeong Hwang and desorption temperatures of styrene on a Ge surface using scanning tunneling microscopy (STM), temperature that styrene molecules attach via the vinyl group in two adsorption configurations: (i) on the top of single Ge

  18. High speed flow cytometric separation of viable cells

    DOE Patents [OSTI]

    Sasaki, Dennis T. (Mountain View, CA); Van den Engh, Gerrit J. (Seattle, WA); Buckie, Anne-Marie (Margate, GB)

    1995-01-01

    Hematopoietic cell populations are separated to provide cell sets and subsets as viable cells with high purity and high yields, based on the number of original cells present in the mixture. High-speed flow cytometry is employed using light characteristics of the cells to separate the cells, where high flow speeds are used to reduce the sorting time.

  19. HIgh Rate X-ray Fluorescence Detector

    SciTech Connect (OSTI)

    Grudberg, Peter Matthew [XIA LLC

    2013-04-30

    The purpose of this project was to develop a compact, modular multi-channel x-ray detector with integrated electronics. This detector, based upon emerging silicon drift detector (SDD) technology, will be capable of high data rate operation superior to the current state of the art offered by high purity germanium (HPGe) detectors, without the need for liquid nitrogen. In addition, by integrating the processing electronics inside the detector housing, the detector performance will be much less affected by the typically noisy electrical environment of a synchrotron hutch, and will also be much more compact than current systems, which can include a detector involving a large LN2 dewar and multiple racks of electronics. The combined detector/processor system is designed to match or exceed the performance and features of currently available detector systems, at a lower cost and with more ease of use due to the small size of the detector. In addition, the detector system is designed to be modular, so a small system might just have one detector module, while a larger system can have many â?? you can start with one detector module, and add more as needs grow and budget allows. The modular nature also serves to simplify repair. In large part, we were successful in achieving our goals. We did develop a very high performance, large area multi-channel SDD detector, packaged with all associated electronics, which is easy to use and requires minimal external support (a simple power supply module and a closed-loop water cooling system). However, we did fall short of some of our stated goals. We had intended to base the detector on modular, large-area detectors from Ketek GmbH in Munich, Germany; however, these were not available in a suitable time frame for this project, so we worked instead with pnDetector GmbH (also located in Munich). They were able to provide a front-end detector module with six 100 m^2 SDD detectors (two monolithic arrays of three elements each) along with associated preamplifiers; these detectors surpassed the performance we expected to get from the Ketek detectors, however they are housed in a sealed module, which does not offer the ease of repair and expandability weâ??d hoped to achieve with the Ketek SDDâ??s. Our packaging efforts were quite successful, as we came up with a very compact way to mount the detector and to house the associated electronics, as well as a very effective way to reliably take out the heat (from the electronics as well as the detectorâ??s Peltier coolers) without risk of condensation and without external airflow or vibration, which could create problems for the target applications. While we were able to design compact processing electronics that fit into the detector assembly, they are still at the prototype stage, and would require a significant redesign to achieve product status. We have not yet tested this detector at a synchrotron facility; we do still plan on working with some close contacts at the nearby Stanford Synchrotron Radiation Laboratory (SSRL) to get some testing with the beam (using existing commercial electronics for readout, as the integrated processor is not ready for use).

  20. Constraints on millicharged neutrinos via analysis of data from atomic ionizations with germanium detectors at sub-keV sensitivities

    E-Print Network [OSTI]

    Jiunn-Wei Chen; Hsin-Chang Chi; Hau-Bin Li; C. -P. Liu; Lakhwinder Singh; Henry T. Wong; Chih-Liang Wu; Chih-Pan Wu

    2014-07-31

    With the advent of detectors with sub-keV sensitivities, atomic ionization has been identified as a promising avenue to probe possible neutrino electromagnetic properties. The interaction cross-sections induced by millicharged neutrinos are evaluated with the ab-initio multi-configuration relativistic random-phase approximation. There is significant enhancement at atomic binding energies compared to that when the electrons are taken as free particles. Positive signals would distinctly manifest as peaks at specific energies with known intensity ratios. Selected reactor neutrino data with germanium detectors at analysis threshold as low as 300 eV are studied. No such signatures are observed, and a combined limit on the neutrino charge fraction of | \

  1. Large-Mass Ultra-Low Noise Germanium Detectors: Performance and Applications in Neutrino and Astroparticle Physics

    E-Print Network [OSTI]

    P. S. Barbeau; J. I. Collar; O. Tench

    2007-01-07

    A new type of radiation detector, a p-type modified electrode germanium diode, is presented. The prototype displays, for the first time, a combination of features (mass, energy threshold and background expectation) required for a measurement of coherent neutrino-nucleus scattering in a nuclear reactor experiment. The device hybridizes the mass and energy resolution of a conventional HPGe coaxial gamma spectrometer with the low electronic noise and threshold of a small x-ray semiconductor detector, also displaying an intrinsic ability to distinguish multiple from single-site particle interactions. The present performance of the prototype and possible further improvements are discussed, as well as other applications for this new type of device in neutrino and astroparticle physics (double-beta decay, neutrino magnetic moment and WIMP searches).

  2. Alleviation of fermi-level pinning effect at metal/germanium interface by the insertion of graphene layers

    SciTech Connect (OSTI)

    Baek, Seung-heon Chris; Seo, Yu-Jin; Oh, Joong Gun; Albert Park, Min Gyu; Bong, Jae Hoon; Yoon, Seong Jun; Lee, Seok-Hee, E-mail: seokheelee@ee.kaist.ac.kr [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Seo, Minsu; Park, Seung-young [Division of Materials Science, Korea Basic Science Institute (KBSI), 169-148 Daehak-ro, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Park, Byong-Guk [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2014-08-18

    In this paper, we report the alleviation of the Fermi-level pinning on metal/n-germanium (Ge) contact by the insertion of multiple layers of single-layer graphene (SLG) at the metal/n-Ge interface. A decrease in the Schottky barrier height with an increase in the number of inserted SLG layers was observed, which supports the contention that Fermi-level pinning at metal/n-Ge contact originates from the metal-induced gap states at the metal/n-Ge interface. The modulation of Schottky barrier height by varying the number of inserted SLG layers (m) can bring about the use of Ge as the next-generation complementary metal-oxide-semiconductor material. Furthermore, the inserted SLG layers can be used as the tunnel barrier for spin injection into Ge substrate for spin-based transistors.

  3. 'Naked' Crystals go Underground

    E-Print Network [OSTI]

    Hans Volker Klapdor-Kleingrothaus

    2003-07-26

    On May 5, 2003 in the GRAN SASSO Underground Laboratory the first naked high-purity Germanium detectors were installed successfully in liquid nitrogen in the GENIUS-Test-Facility (GENIUS-TF). This is the first time ever that this novel technique for extreme background reduction in searches for rare decays is going to be tested under realistic background conditions.

  4. HIGH-TECH MATERIALS ALERT SEPTEMBER 04, 2006

    E-Print Network [OSTI]

    Azad, Abdul-Majeed

    HIGH-TECH MATERIALS ALERT SEPTEMBER 04, 2006 TECHNICAL INSIGHTS ALERT Phone: 210-348-1000 Use-steam reforming becomes a non-issue. Notably, it was observed that by modifying the #12;High-Tech Materials Alert method to generate high-purity hydrogen. Metal-steam reforming basically deals with a reaction between

  5. 24th European Photovoltaic Solar Energy Conference, Hamburg, Germany, Sept. 2009 FORMATION OF MESOPOROUS GERMANIUM BY ELECTROCHEMICAL ETCHING FOR LIFT-OFF

    E-Print Network [OSTI]

    %. Keywords: Germanium, Space, Layer transfer processes 1 INTRODUCTION The reduction of weight of multi-junction III-V semiconductor solar cells is an important issue for space applications because of cost reduction-V space solar cell is a monolithic Ga0.5In0.5P/Ga0.99In0.01As/Ge triple-junction cell grown lattice

  6. A multi-scale analysis of the impact of pressure on melting of crystalline phase change material germanium telluride

    SciTech Connect (OSTI)

    Liu, Jie, E-mail: liujie@uw.edu [Department of Electrical Engineering, University of Washington, 185 Stevens Way, Paul Allen Center, Seattle, Washington 98195 (United States)

    2014-10-27

    The impact of the moderate pressure (about 10{sup 0?}GPa) on the melting of crystalline (c-) phase change material (PCM) germanium telluride (GeTe) is analyzed, by combining the heat transfer equation in the PCM device scale (10{sup 1}–10{sup 2?}nm and beyond), and the ab initio molecular dynamics and the nudged elastic band simulations in the atomistic scale (10{sup ?1}–10{sup 0?}nm). The multi-scale analysis unravels that a pressure P?=?1.0?GPa can increase the melting temperature of c-GeTe and the PCM device “reset” operation energy consumption by 6%–7%. It is shown that the melting temperature increase originates from the pressure-induced raise of the energy barrier of the umbrella-flip transition of the Ge atom from the octahedral symmetry site to the tetrahedral symmetry site. It is revealed that when P?>?1.0?GPa, which is normal in PCM devices, the “reset” energy will be increased even by more. Based on the analysis, suggestions to alleviate pressure-induced raise of melting temperature and “reset” energy are provided.

  7. The potential of large germanium detector arrays for solar-axion searches utilizing the axio-electric effect for detection

    E-Print Network [OSTI]

    F. T. Avignone III

    2009-02-02

    The sensitivities of large arrays of low-background germanium detectors for solar axion searches are investigated in the context of three coupling scenarios. A search was made for the 14.4-keV axion branch from the M1-transition in the thermally excited 57Fe in the solar core in 80 kgd of data from the IGEX Dark Matter experiment published earlier. In one scenario, the direct couplings of axions to hadrons and to electrons were assumed to be in the range of Peccei-Quinn (PQ) scale, 3x105 GeV < fPQ < 7x105 GeV. This scenario is excluded by the IGEX data. In a second case, at the same PQ scale, coupling to photons and to electrons are suppressed. The IGEX data partially excludes this scenario depending on the degree of suppression. In the third case, the PQ-scale for all couplings is assumed to be in the range: 3x106 GeV< fPQ <7x106 GeV. Detection rates in Ge for all three scenarios are presented.

  8. Advancing the Technology Base for High Temperature Hydrogen Membranes

    SciTech Connect (OSTI)

    Dye, Robert C.; Moss, Thomas S.

    1997-12-31

    High purity hydrogen is a critical component for at least two major industrial processes: 1) the refining of conventional steels and raw pig iron into low carbon steels and high purity iron used for high performance magnets in motors, generators, alternators, transformers, and etc.; and 2) refining metallurgical grade silicon to the high- purity, polycrystalline silicon used in fabricating single crystal silicon wafers for semiconductor manufacturing. In the process of producing low carbon iron products, CO and CO2 impurities prevent efficient removal of the carbon already in the raw iron. In the refining of metallurgical grade silicon, the presence of any impurity above the part-per- million level prevents the ultimate fabrication of the large scale single crystals that are essential to the semiconductor device. In a lesser magnitude role, high quality hydrogen is used in a variety of other processes, including specialty metals refining (e.g., iridium, osmium, palladium, platinum, and ruthenium) and R{ampersand}D in areas such as organic synthesis and development of certain types of fuel cells. In all of these applications, a high-temperature hydrogen membrane can provide a method for achieving a very high purity level of hydrogen in a manner that is more economical and/or more rugged than existing techniques.

  9. High volume production of nanostructured materials

    DOE Patents [OSTI]

    Ripley, Edward B. (Knoxville, TN); Morrell, Jonathan S. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Ludtka, Gerard M. (Oak Ridge, TN)

    2009-10-13

    A system and method for high volume production of nanoparticles, nanotubes, and items incorporating nanoparticles and nanotubes. Microwave, radio frequency, or infrared energy vaporizes a metal catalyst which, as it condenses, is contacted by carbon or other elements such as silicon, germanium, or boron to form agglomerates. The agglomerates may be annealed to accelerate the production of nanotubes. Magnetic or electric fields may be used to align the nanotubes during their production. The nanotubes may be separated from the production byproducts in aligned or non-aligned configurations. The agglomerates may be formed directly into tools, optionally in compositions that incorporate other materials such as abrasives, binders, carbon-carbon composites, and cermets.

  10. Measurement of the cross sections for the production of the isotopes {sup 74}As, {sup 68}Ge, {sup 65}Zn, and {sup 60}Co from natural and enriched germanium irradiated with 100-MeV protons

    SciTech Connect (OSTI)

    Barabanov, I. R.; Bezrukov, L. B.; Gurentsov, V. I.; Zhuykov, B. L.; Kianovsky, S. V.; Kornoukhov, V. N.; Kohanuk, V. M.; Yanovich, E. A. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

    2010-07-15

    The cross sections for the production of the radioactive isotopes {sup 74}As, {sup 68}Ge, {sup 65}Zn, and {sup 60}Co in metallic germanium irradiated with 100-MeV protons were measured, the experiments being performed both with germanium of natural isotopic composition and germanium enriched in the isotope {sup 76}Ge. The targets were irradiated with a proton beam at the facility for the production of radionuclides at the accelerator of the Institute for Nuclear Research (INR, Moscow). The data obtained will further be used to calculate the background of radioactive isotopes formed by nuclear cascades of cosmic-ray muons in new-generation experiments devoted to searches for the neutrinoless double-beta decay of {sup 76}Ge at underground laboratories.

  11. Steering of an ultrarelativistic proton beam by a bent germanium crystal

    SciTech Connect (OSTI)

    De Salvador, D.; Carturan, S.; Bazzan, M.; Argiolas, N.; Carnera, A.; Bagli, E.; Mazzolari, A.; Lytovchenko, O.; Della Mea, G.; Guidi, V.; Bolognini, D.; Hasan, S.; Prest, M.; Vallazza, E.

    2011-06-06

    Curved crystals, thanks to the electrostatic potential generated by the coherent atomic structure, may deflect ultrarelativistic charged particles by means of channeling and volume reflection effects. Most of the experimental knowledge about these phenomena was gathered with Si crystals, though the performance could be improved by using materials with a larger atomic number. In this letter, we investigate planar and axial channeling and volume reflection in a high quality Ge short strip crystal. All the effects are demonstrated to occur in agreement with theoretical expectations, which take into account the stronger confinement potential for an ideal Ge crystal.

  12. Ballistic electron transport calculation of strained germanium-tin fin field-effect transistors

    SciTech Connect (OSTI)

    Lan, H.-S.; Liu, C. W.

    2014-05-12

    The dependence of ballistic electron current on Sn content, sidewall orientations, fin width, and uniaxial stress is theoretically studied for the GeSn fin field-effect transistors. Alloying Sn increases the direct ? valley occupancy and enhances the injection velocity at virtual source node. (112{sup ¯}) sidewall gives the highest current enhancement due to the rapidly increasing ? valley occupancy. The non-parabolicity of the ? valley affects the occupancy significantly. However, uniaxial tensile stress and the shrinkage of fin width reduce the ? valley occupancy, and the currents are enhanced by increasing occupancy of specific indirect L valleys with high injection velocity.

  13. Evolution of microstructural defects with strain effects in germanium nanocrystals synthesized at different annealing temperatures

    SciTech Connect (OSTI)

    Zhang, Minghuan; Cai, Rongsheng; Zhang, Yujuan; Wang, Chao [The Cultivation Base for State Key Laboratory, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); College of Chemistry and Chemical Engineering, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); Wang, Yiqian, E-mail: yqwang@qdu.edu.cn [The Cultivation Base for State Key Laboratory, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); College of Physics Science, Qingdao University, No. 308, Ningxia Road, Qingdao 266071 (China); Ross, Guy G.; Barba, David [INRS-EMT, 1650 Boulevard Lionel-Boulet, Varennes, Quebec J3X 1S2 (Canada)

    2014-07-01

    Ge nanocrystals (Ge-ncs) were produced by implantation of {sup 74}Ge{sup +} into a SiO{sub 2} film on (100) Si, followed by high-temperature annealing from 700 °C to 1100 °C. Transmission electron microscopy (TEM) studies show that the average size of Ge-ncs increases with the annealing temperature. High-resolution TEM (HRTEM) investigations reveal the presence of planar and linear defects in the formed Ge-ncs, whose relative concentrations are determined at each annealing temperature. The relative concentration of planar defects is almost independent of the annealing temperature up to 1000 °C. However, from 1000 °C to 1100 °C, its concentration decreases dramatically. For the linear defects, their concentration varies considerably with the annealing temperatures. In addition, by measuring the interplanar spacing of Ge-ncs from the HRTEM images, a strong correlation is found between the dislocation percentage and the stress field intensity. Our results provide fundamental insights regarding both the presence of microstructural defects and the origin of the residual stress field within Ge-ncs, which can shed light on the fabrication of Ge-ncs with quantified crystallinity and appropriate size for the advanced Ge-nc devices. - Highlights: • Growth of Ge nanocrystals at different annealing temperatures was investigated. • Strain field has great effects on the formation of dislocations. • Different mechanisms are proposed to explain growth regimes of Ge nanocrystals.

  14. Workshop on nuclear structure at moderate and high spin: Slide report

    SciTech Connect (OSTI)

    Not Available

    1986-10-01

    The workshop was scheduled to coincide with the beginning of operation of a number of large arrays of Compton-suppressed germanium detectors. The workshop was divided into 14 sessions containing 3 presentations each. The topics of these sessions were superdeformation, heavy rare earths, single-particle configurations, band termination, continuum properties, light rare-earths, new techniques, high temperatures, transfer reactions, transition region, shapes, lifetimes, and moments. This publication consists of the slides used in all of the presentations at the workshop.

  15. Production of aluminum-silicon alloy and ferrosilicon and commercial purity aluminum by the direct reduction process. Second annual technical report for the period 1978 September 1-1979 December 31

    SciTech Connect (OSTI)

    Bruno, M.J.

    1980-10-01

    A new computer program was developed for simultaneously solving heat and mass balance at steady state for a flowing one-dimensional chemical reactor. Bench scale reactor results confirmed that minimum final stage reaction temperature is 1950 to 2000/sup 0/C, depending on the Fe/sub 2/O/sub 3/ concentration in the burden. Additions of Fe/sub 2/O/sub 3/ to the charge produced significant increase in metallic yield. A new bench reactor was designed, built, and operated to facilitate semi-continuous operation, using O/sub 2/ injection to burn coke supporting the burden, resulting in burden movement. Validity of the equipment and test procedures was demonstrated by successfully operating the reactor as an iron blast furnace at 1500/sup 0/C. Bench scale fractional crystallizer runs were continued to determine the impurity effects of Fe up to 6.9% and Ti up to 1.25% on alloy product purity and yield. High initial impurity concentrations resulted in less pure Al-Si product and product yield below 50% due to Al and Si losses as Fe-Si-Al and Ti-Si-Al intermetallics. Long term testing was continued in the large bench scale membrane cell to evaluate woven cloth membrane and other construction materials, operating procedures, and effects of operating parameters on cell performance. Included in the latter were starting alloy composition, current density, anode-cathode spacing, and electrolyte composition.

  16. Signal recognition efficiencies of artificial neural-network pulse-shape discrimination in HPGe $0???$-decay searches

    E-Print Network [OSTI]

    A. Caldwell; F. Cossavella; B. Majorovits; D. Palioselitis; O. Volynets

    2015-07-21

    A pulse-shape discrimination method based on artificial neural networks was applied to pulses simulated for different background, signal and signal-like interactions inside a germanium detector. The simulated pulses were used to investigate variations of efficiencies as a function of used training set. It is verified that neural networks are well-suited to identify background pulses in true-coaxial high-purity germanium detectors. The systematic uncertainty on the signal recognition efficiency derived using signal-like evaluation samples from calibration measurements is estimated to be 5\\%. This uncertainty is due to differences between signal and calibration samples.

  17. Role of hydrogen in hydrogen-induced layer exfoliation of germanium J. M. Zahler,1 A. Fontcuberta i Morral,1,2 M. J. Griggs,1 Harry A. Atwater,1 and Y. J. Chabal3

    E-Print Network [OSTI]

    Atwater, Harry

    Role of hydrogen in hydrogen-induced layer exfoliation of germanium J. M. Zahler,1 A. Fontcuberta i 2006; published 9 January 2007 The role of hydrogen in the exfoliation of Ge is studied using cross for the physical and chemical action of hydrogen in the exfoliation of these materials is presented, in which H

  18. Method and apparatus for measuring lung density by Compton backscattering

    DOE Patents [OSTI]

    Loo, Billy W. (Oakland, CA); Goulding, Frederick S. (Lafayette, CA)

    1991-01-01

    The density of the lung of a patient suffering from pulmonary edema is monitored by irradiating the lung by a single collimated beam of monochromatic photons and measuring the energies of photons Compton backscattered from the lung by a single high-resolution, high-purity germanium detector. A compact system geometry and a unique data extraction scheme are utilized to monimize systematic errors due to the presence of the chestwall and multiple scattering.

  19. Method and apparatus for measuring lung density by Compton backscattering

    DOE Patents [OSTI]

    Loo, B.W.; Goulding, F.S.

    1988-03-11

    The density of the lung of a patient suffering from pulmonary edema is monitored by irradiating the lung by a single collimated beam of monochromatic photons and measuring the energies of photons compton back-scattered from the lung by a single high-resolution, high-purity germanium detector. A compact system geometry and a unique data extraction scheme are utilized to minimize systematic errors due to the presence of the chestwall and multiple scattering. 11 figs., 1 tab.

  20. Synthesis of High-Purity alpha-and beta-PbO and Possible Applications to Synthesis and Processing of Other Lead Oxide Materials

    E-Print Network [OSTI]

    Perry, Dale L.

    2011-01-01

    structural forms of lead(II) oxide X-ray diffractionand Processing of Other Lead Oxide Materials D. L. PERRY andThe red, tetragonal form of lead oxide, ?-PbO, litharge, and

  1. Synthesis of High-Purity alpha-and beta-PbO and Possible Applications to Synthesis and Processing of Other Lead Oxide Materials

    SciTech Connect (OSTI)

    Perry, Dale L.; Wilkinson, T. J.

    2009-11-12

    The red, tetragonal form of lead oxide, alpha-PbO, litharge, and the yellow, orthorhombic form, beta-PbO, massicot, have been synthesized from lead(II) salts in aqueous media at elevated temperature. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the size, morphology, and crystallographic structural forms of the products. The role of impurities in the experimental synthesis of the materials and microstructural variations in the final products are described, and the implications of these observations with respect to the synthesis of different conducting lead oxides and other related materials are discussed.

  2. Synthesis of High-Purity alpha-and beta-PbO and Possible Applications to Synthesis and Processing of Other Lead Oxide Materials

    E-Print Network [OSTI]

    Perry, Dale L.

    2011-01-01

    and Processing of Other Lead Oxide Materials D. L. PERRY andred, tetragonal form of lead oxide, ?-PbO, litharge, and thedifferent conducting lead oxides and other related materials

  3. Limits on Low-Mass WIMP Dark Matter with an Ultra-Low-Energy Germanium Detector at 220 eV Threshold

    E-Print Network [OSTI]

    Shin-Ted Lin; H. T. Wong; for the TEXONO Collaboration

    2008-10-20

    An energy threshold of (220$\\pm$10) eV was achieved at an efficiency of 50% with a four-channel ultra-low-energy germanium detector each with an active mass of 5 g\\cite{wimppaper}. This provides a unique probe to WIMP dark matter with mass below 10 GeV. With low background data taken at the Kuo-Sheng Laboratory, constraints on WIMPs in the galactic halo were derived. Both spin-independent WIMP-nucleon and spin-dependent WIMP-neutron bounds improve over previous results for WIMP mass between 3$-$6 GeV. These results, together with those on spin-dependent couplings, will be presented. Sensitivities for full-scale experiments were projected. This detector technique makes the unexplored sub-keV energy window accessible for new neutrino and dark matter experiments.

  4. Methods for high volume production of nanostructured materials

    DOE Patents [OSTI]

    Ripley, Edward B. (Knoxville, TN); Morrell, Jonathan S. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Ludtka, Gerald M. (Oak Ridge, TN)

    2011-03-22

    A system and method for high volume production of nanoparticles, nanotubes, and items incorporating nanoparticles and nanotubes. Microwave, radio frequency, or infrared energy vaporizes a metal catalyst which, as it condenses, is contacted by carbon or other elements such as silicon, germanium, or boron to form agglomerates. The agglomerates may be annealed to accelerate the production of nanotubes. Magnetic or electric fields may be used to align the nanotubes during their production. The nanotubes may be separated from the production byproducts in aligned or non-aligned configurations. The agglomerates may be formed directly into tools, optionally in compositions that incorporate other materials such as abrasives, binders, carbon-carbon composites, and cermets.

  5. Axes determination for segmented true-coaxial HPGe detectors

    E-Print Network [OSTI]

    I. Abt; A. Caldwell; J. Liu; B. Majorovits; P. Petrov; O. Volynets

    2012-03-26

    A fast method to determine the crystallographic axes of segmented true-coaxial high-purity germanium detectors is presented. It is based on the analysis of segment-occupancy patterns obtained by irradiation with radioactive sources. The measured patterns are compared to predictions for different axes orientations. The predictions require a simulation of the trajectories of the charge carriers taking the transverse anisotropy of their drift into account.

  6. Handheld isotope identification system

    DOE Patents [OSTI]

    Frankle, Christen M. (Los Alamos, NM); Becker, John A. (Alameda, CA); Cork, Christopher P. (Pleasant Hill, CA); Madden, Norman W. (Livermore, CA)

    2007-01-09

    A portable radiation detector using a high-purity germanium crystal as the sensing device. The crystal is fabricated such that it exhibits a length to width ratio greater than 1:1 and is oriented within the detector to receive radiation along the width of said crystal. The crystal is located within a container pressurized with ultra-pure nitrogen, and the container is located within a cryostat under vacuum.

  7. Investigation of Naturally Occurring Radio Nuclides in Shir-kuh Granites

    SciTech Connect (OSTI)

    Mazarei, Mohammad Mehdi; Zarei, Mojtaba

    2011-12-26

    One of the principle natural radiation resources is Granite which can be dangerous for human because of its radiations. Based on this fact, in this research we attempt to specify the activity amount of these natural radio nuclides, existing in Shir-kuh Granite of Yazd state. To specify the activity amount of this natural radio nuclides, it has been applied the measurement method of Gamma spectroscopy using high purity Germanium (HPGe) detector.

  8. Pulse shape discrimination studies with a Broad-Energy Germanium detector for signal identification and background suppression in the GERDA double beta decay experiment

    E-Print Network [OSTI]

    Dušan Budjáš; Marik Barnabé Heider; Oleg Chkvorets; Nikita Khanbekov; Stefan Schönert

    2009-09-22

    First studies of event discrimination with a Broad-Energy Germanium (BEGe) detector are presented. A novel pulse shape method, exploiting the characteristic electrical field distribution inside BEGe detectors, allows to identify efficiently single-site events and to reject multi-site events. The first are typical for neutrinoless double beta decays (0-nu-2-beta) and the latter for backgrounds from gamma-ray interactions. The obtained survival probabilities of backgrounds at energies close to Q(76Ge) = 2039 keV are 0.93% for events from 60Co, 21% from 226Ra and 40% from 228Th. This background suppression is achieved with 89% acceptance of 228Th double escape events, which are dominated by single site interactions. Approximately equal acceptance is expected for 0-nu-2-beta-decay events. Collimated beam and Compton coincidence measurements demonstrate that the discrimination is largely independent of the interaction location inside the crystal and validate the pulse-shape cut in the energy range of Q(76Ge). The application of BEGe detectors in the GERDA and the Majorana double beta decay experiments is under study.

  9. Test of Purity by LOCC

    E-Print Network [OSTI]

    Keiji Matsumoto

    2010-09-16

    Given n-copies of unknown bipartite (possiblly mixed) state, our task is to test whether the state is a pure state of not. Allowed to use the global operations, optimal one-sided error test is the projection onto the symmetric subspace, obviously. Is it possible to approximate the globally optimal measurement by LOCC when n is large?

  10. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01

    Motivation Multi-junction (MJ) solar cells show particular promise as a future clean renewable energy

  11. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01

    III! V Multijunction Solar Cells,” (2003). J. F. Geisz, etEfficiency Multi-Junction Solar Cells A thesis submitted inEfficiency Multi-Junction Solar Cells By David Michael Fong

  12. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01

    technique for LM triple junction solar cell grown on porousAnother common triple-junction solar cell utilizes a GaAstechnique for LM triple junction solar cell grown on porous

  13. GERDA phase II detectors: Behind the production and characterisation at low background conditions

    SciTech Connect (OSTI)

    Maneschg, Werner [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)] [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Collaboration: GERDA Collaboration; and others

    2013-08-08

    The low background GERmanium Detector Array (GERDA) at Laboratori Nazionali del Gran Sasso (LNGS) is designed to search for the rare neutrinoless double beta decay (0???) in {sup 76}Ge. Bare germanium diodes are operated in liquid argon which is used as coolant, as passive and soon active as well shield against external radiation. Currently, Phase I of the experiment is running using ?15 kg of co-axial High Purity Germanium diodes. In order to increase the sensitivity of the experiment 30 Broad Energy Germanium (BEGe) diodes will be added within 2013. This presentation reviews the production chain of the new BEGe detectors from isotopic enrichment to diode production and testing. As demonstrated all steps were carefully planned in order to minimize the exposure of the enriched germanium to cosmic radiation. Following this premise, acceptance and characterisation measurement of the newly produced diodes have been performed within the HEROICA project in the Belgian underground laboratory HADES close to the diode manufacturer. The test program and the results from a subset of the recently terminated GERDA Phase II BEGe survey will be presented.

  14. Observation of memory effect in germanium nanocrystals embedded in an amorphous silicon oxide matrix of a metalinsulator

    E-Print Network [OSTI]

    at the silicon­tunnel oxide interface, forming trap sites that can degrade device performance. Recently, we. The memory effect was manifested by the hysteresis in the C­V curve. Transmission electron microscope and C electronics and embedded systems has resulted in a need for low-power high-density nonvolatile memories

  15. NIF Status Update - 2014

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    germanium filters were used to reduce the high-energy background. Germanium and zirconium x-ray sources allowed for a direct comparison of diffraction efficiency. Four...

  16. Microstructure and mechanical properties of thermoelectric nanostructured n-type silicon-germanium alloys synthesized employing spark plasma sintering

    SciTech Connect (OSTI)

    Bathula, Sivaiah [CSIR-Network of Institutes for Solar Energy, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Department of Applied Physics, Delhi Technological University, Delhi (India); Gahtori, Bhasker; Tripathy, S. K.; Tyagi, Kriti; Srivastava, A. K.; Dhar, Ajay, E-mail: adhar@nplindia.org [CSIR-Network of Institutes for Solar Energy, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Jayasimhadri, M. [Department of Applied Physics, Delhi Technological University, Delhi (India)

    2014-08-11

    Owing to their high thermoelectric (TE) figure-of-merit, nanostructured Si{sub 80}Ge{sub 20} alloys are evolving as a potential replacement for their bulk counterparts in designing efficient radio-isotope TE generators. However, as the mechanical properties of these alloys are equally important in order to avoid in-service catastrophic failure of their TE modules, we report the strength, hardness, fracture toughness, and thermal shock resistance of nanostructured n-type Si{sub 80}Ge{sub 20} alloys synthesized employing spark plasma sintering of mechanically alloyed nanopowders of its constituent elements. These mechanical properties show a significant enhancement, which has been correlated with the microstructural features at nano-scale, delineated by transmission electron microscopy.

  17. Early diagenesis of germanium in sediments of the Antarctic South Atlantic: In search of the missing Ge sink

    SciTech Connect (OSTI)

    King, S.L.; Froelich, P.N.; Jahnke, R.A.

    2000-04-01

    Pore water and solid-phase geochemistry profiles were obtained from several cores between 41{degree}S and 53{degree}S in the Atlantic sector of the Southern Ocean. Pore water nitrate, manganese, and iron profiles delineate standard redox zones in these sediments, and help characterize those with classic vs. burn-down behaviors. Pore water Si and Ge profiles demonstrate that Ge released during opal dissolution is removed pervasively throughout the uppermost interval of silicate release, and also downwards into the suboxic zone by as yet unidentified precipitation mechanisms. These results indicate that early diagenesis of Ge is uncoupled from that of opal. Solid-phase extractions (Fe, Mn, U, Mo, Ge, Cu, Ni, Co, V, and Cd) in a few cores suggest that anthigenic Ge removal in the suboxic zone is not associated with peaks in authigenic Mn cycling (MnO{sub 2} and related metals) but rather with processes deeper in the sediments, perhaps Fe or U diagenesis. Below the interval of Ge removal, pre water Ge increases linearly with depth by over two orders of magnitude, indicating a deep (below recovery) source of large magnitude. The fraction of opal-derived Ge precipitated authigenically in these sediments ranges from {approximately}1 to 96% and correlates strongly with the detrital fraction as well as the detrital to opal ratio, both of which generally decrease from north to south. The Ge sink observed in these sediments would need to be globally representative to account for the entire missing Ge sink in today's oceanic Ge balance, which seems unlikely. Benthic fluxes of Ge and Si estimated from these pore water profiles and from measurements in three benthic flux chamber experiments at high carbon-rain continental margin sites demonstrate that the Ge/Si rate released from the seafloor in locations with high benthic silicate and carbon fluxes is congruent with Holocene opal dissolution (Ge/Si {approximately} 0.7 x 10{sup {minus}6}). In contrast, Ge/Si flux ratios in areas with low silicate fluxes are Ge-depleted (Ge/Si < 0.5 x 10{sup {minus}6}). The authors speculate that glacial-interglacial changes in oceanic Ge/Si as recorded in diatoms may be due in part to variations in this authigenic Ge sink, perhaps related to shifts in siliceous productivity from open ocean (Antarctic) siliceous oozes during interglacials to areas of higher detrital input (Sub Antarctic, continental margins) and possibly also to generally more reducing conditions in sediments during glacials.

  18. High Efficiency Triple-Junction Amorphous Silicon Alloy Photovoltaic Technology, Final Technical Report, 6 March 1998 - 15 October 2001

    SciTech Connect (OSTI)

    Guha, S.

    2001-11-08

    This report describes the research program intended to expand, enhance, and accelerate knowledge and capabilities for developing high-performance, two-terminal multijunction amorphous silicon (a-Si) alloy cells, and modules with low manufacturing cost and high reliability. United Solar uses a spectrum-splitting, triple-junction cell structure. The top cell uses an amorphous silicon alloy of {approx}1.8-eV bandgap to absorb blue photons. The middle cell uses an amorphous silicon germanium alloy ({approx}20% germanium) of {approx}1.6-eV bandgap to capture green photons. The bottom cell has {approx}40% germanium to reduce the bandgap to {approx}1.4-eV to capture red photons. The cells are deposited on a stainless-steel substrate with a predeposited silver/zinc oxide back reflector to facilitate light-trapping. A thin layer of antireflection coating is applied to the top of the cell to reduce reflection loss. The major research activities conducted under this program were: (1) Fundamental studies to improve our understanding of materials and devices; the work included developing and analyzing a-Si alloy and a-SiGe alloy materials prepared near the threshold of amorphous-to-microcrystalline transition and studying solar cells fabricated using these materials. (2) Deposition of small-area cells using a radio-frequency technique to obtain higher deposition rates. (3) Deposition of small-area cells using a modified very high frequency technique to obtain higher deposition rates. (4) Large-area cell research to obtain the highest module efficiency. (5) Optimization of solar cells and modules fabricated using production parameters in a large-area reactor.

  19. A search for particle dark matter using cryogenic germanium and silicon detectors in the one- and two- tower runs of CDMS-II at Soudan

    SciTech Connect (OSTI)

    Ogburn, Reuben Walter, IV; /Stanford U., Phys. Dept.

    2008-04-01

    Images of the Bullet Cluster of galaxies in visible light, X-rays, and through gravitational lensing confirm that most of the matter in the universe is not composed of any known form of matter. The combined evidence from the dynamics of galaxies and clusters of galaxies, the cosmic microwave background, big bang nucleosynthesis, and other observations indicates that 80% of the universe's matter is dark, nearly collisionless, and cold. The identify of the dar, matter remains unknown, but weakly interacting massive particles (WIMPs) are a very good candidate. They are a natural part of many supersymmetric extensions to the standard model, and could be produced as a nonrelativistic, thermal relic in the early universe with about the right density to account for the missing mass. The dark matter of a galaxy should exist as a spherical or ellipsoidal cloud, called a 'halo' because it extends well past the edge of the visible galaxy. The Cryogenic Dark Matter Search (CDMS) seeks to directly detect interactions between WIMPs in the Milky Way's galactic dark matter halo using crystals of germanium and silicon. Our Z-sensitive ionization and phonon ('ZIP') detectors simultaneously measure both phonons and ionization produced by particle interactions. In order to find very rare, low-energy WIMP interactions, they must identify and reject background events caused by environmental radioactivity, radioactive contaminants on the detector,s and cosmic rays. In particular, sophisticated analysis of the timing of phonon signals is needed to eliminate signals caused by beta decays at the detector surfaces. This thesis presents the firs two dark matter data sets from the deep underground experimental site at the Soudan Underground Laboratory in Minnesota. These are known as 'Run 118', with six detectors (1 kg Ge, 65.2 live days before cuts) and 'Run 119', with twelve detectors (1.5 kg Ge, 74.5 live days before cuts). They have analyzed all data from the two runs together in a single, combined analysis, with sensitivity to lower-energy interactions, careful control of data quality and stability, and further development of techniques for reconstructing event location and rejecting near-surface interactions from beta decays. They also present a revision to the previously published Run 119 analysis, a demonstration of the feasibility of a low-threshold (1 or 2 keV) analysis of Soudan data, and a review of the literature on charge generation and quenching relevant to the ionization signal.

  20. The MGDO software library for data analysis in Ge neutrinoless double-beta decay experiments

    E-Print Network [OSTI]

    M. Agostini; J. A. Detwiler; P. Finnerty; K. Kröninger; D. Lenz; J. Liu; M. G. Marino; R. Martin; K. D. Nguyen; L. Pandola; A. G. Schubert; O. Volynets; P. Zavarise

    2011-11-30

    The GERDA and Majorana experiments will search for neutrinoless double-beta decay of germanium-76 using isotopically enriched high-purity germanium detectors. Although the experiments differ in conceptual design, they share many aspects in common, and in particular will employ similar data analysis techniques. The collaborations are jointly developing a C++ software library, MGDO, which contains a set of data objects and interfaces to encapsulate, store and manage physical quantities of interest, such as waveforms and high-purity germanium detector geometries. These data objects define a common format for persistent data, whether it is generated by Monte Carlo simulations or an experimental apparatus, to reduce code duplication and to ease the exchange of information between detector systems. MGDO also includes general-purpose analysis tools that can be used for the processing of measured or simulated digital signals. The MGDO design is based on the Object-Oriented programming paradigm and is very flexible, allowing for easy extension and customization of the components. The tools provided by the MGDO libraries are used by both GERDA and Majorana.

  1. DETECTOR MATERIALS: GERMANIUM AND SILICON

    E-Print Network [OSTI]

    Haller, E.E.

    2010-01-01

    most important for the radiation detection will be reviewedones for nuclear radiation detection are what we call the

  2. Enhancing the detector for advanced neutron capture experiments

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Couture, A.; Mosby, S.; Baramsai, B.; Bredeweg, T. A.; Jandel, M.; Macon, K.; O’Donnell, J. M.; Rusev, G.; Taddeucci, T. N; Ullmann, J. L.; et al

    2015-05-28

    The Detector for Advanced Neutron Capture Experiments (DANCE) has been used for extensive studies of neutron capture, gamma decay, photon strength functions, and prompt and delayed fission-gamma emission. Despite these successes, the potential measurements have been limited by the data acquisition hardware. We report on a major upgrade of the DANCE data acquisition that simultaneously enables strait-forward coupling to auxiliary detectors, including high-resolution high-purity germanium detectors and neutron tagging array. The upgrade will enhance the time domain accessible for time-of-flight neutron measurements as well as improve the resolution in the DANCE barium fluoride crystals for photons.

  3. The Majorana low-noise low-background front-end electronics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abgrall, N.; Aguayo, E.; Avignone, III, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; et al

    2015-03-24

    The Majorana Demonstrator will search for the neutrinoless double beta decay (??(0?)) of the isotope ??Ge with a mixed array of enriched and natural germanium detectors. In view of the next generation of tonne-scale germanium-based ??(0?)-decay searches, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest (ROI) around the 2039-keV Q-value of the ??Ge ??(0?)-decay. Such a requirement on the background level significantly constrains the design of the readout electronics, which is further driven by noise and energy resolutionmore »performances. We present here the low-noise low-background front-end electronics developed for the low-capacitance p-type point contact (P-PC) germanium detectors of the Majorana Demonstrator. This resistive-feedback front-end, specifically designed to have low mass, is fabricated on a radioassayed fused-silica substrate where the feedback resistor consists of a sputtered thin film of high purity amorphous germanium and the feedback capacitor is based on the capacitance between gold conductive traces.« less

  4. The Majorana low-noise low-background front-end electronics

    SciTech Connect (OSTI)

    Abgrall, N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Aguayo, E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Avignone, III, F. T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of South Carolina, Columbia, SC (United States); Barabash, A. S. [Institute for Theoretical and Experiemental Physics, Moscow (Russia); Bertrand, F. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boswell, M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brudanin, V. [Joint Institute for Nuclear Research, Durham, NC (United States); Busch, M. [Duke Univ., Durham, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Byram, D. [Univ. of South Dakota, Vermillion, SD (United States); Caldwell, A. S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Chan, Y. -D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Christofferson, C. D. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Combs, D. C. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Cuesta, C. [Univ. of Washington, Seattle, WA (United States); Detwiler, J. A. [Univ. of Washington, Seattle, WA (United States); Doe, P. J. [Univ. of Washington, Seattle, WA (United States); Efremenko, Yu. [Univ. of Tennessee, Knoxville, TN (United States); Egorov, V. [Joint Institute for Nuclear Research, Durham, NC (United States); Ejiri, H. [Osaka Univ., Osaka (Japan); Elliott, S. R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fast, J. E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Finnerty, P. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Fraenkle, F. M. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giovanetti, G. K. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Goett, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gruszko, J. [Univ. of Washington, Seattle, WA (United States); Guiseppe, V. E. [Univ. of South Carolina, Columbia, SC (United States); Gusev, K. [Joint Institute for Nuclear Research, Durham, NC (United States); Hallin, A. L. [Univ. of Alberta, Edmonton, AB (Canada); Hazama, R. [Osaka Univ., Osaka (Japan); Hegai, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); North Carolina State Univ., Raleigh, NC (United States); Henning, R. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Hoppe, E. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Howard, S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Howe, M. A. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Keeter, K. J. [Black Hills State Univ., Spearfish, SD (United States); Kidd, M. F. [Tennessee Tech Univ., Cookeville, TN (United States); Kochetov, O. [Joint Institute for Nuclear Research, Durham, NC (United States); Konovalov, S. I. [Institute for Theoretical and Experiemental Physics, Moscow (Russia); Kouzes, R. T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); LaFerriere, B. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leon, J. [Univ. of Washington, Seattle, WA (United States); Leviner, L. E. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Loach, J. C. [Shanghai Jiao Tong Univ., Shanghai (China); MacMullin, J. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States)

    2015-01-01

    The Majorana Demonstrator will search for the neutrinoless double beta decay (??(0?)) of the isotope ??Ge with a mixed array of enriched and natural germanium detectors. In view of the next generation of tonne-scale germanium-based ??(0?)-decay searches, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest (ROI) around the 2039-keV Q-value of the ??Ge ??(0?)-decay. Such a requirement on the background level significantly constrains the design of the readout electronics, which is further driven by noise and energy resolution performances. We present here the low-noise low-background front-end electronics developed for the low-capacitance p-type point contact (P-PC) germanium detectors of the Majorana Demonstrator. This resistive-feedback front-end, specifically designed to have low mass, is fabricated on a radioassayed fused-silica substrate where the feedback resistor consists of a sputtered thin film of high purity amorphous germanium and the feedback capacitor is based on the capacitance between gold conductive traces.

  5. A dark matter search with MALBEK

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Giovanetti, G. K.; Abgrall, N.; Aguayo, E.; Avignone, III, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; et al

    2015-01-01

    The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of ??Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its sub-keV energy threshold, this detector is sensitive to potential non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and explore the impact of slow surfacemore »event contamination when searching for a WIMP signal.« less

  6. The MAJORANA DEMONSTRATOR for 0???: Current Status and Future Plans

    SciTech Connect (OSTI)

    Green, M.P.; Abgrall, N.; Aguayo, E.; Avignone, F.T.; Barabash, A.S.; Bertrand, F.E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A.S.; Chan, Y.-D.; Christofferson, C.D.; Combs, D.C.; Cuesta, C.; Detwiler, J.A.; Doe, P.J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S.R.; Fast, J.E.; Finnerty, P.; Fraenkle, F.M.; Galindo-Uribarri, A.; Giovanetti, G.K.; Goett, J.; Gruszko, J.; Guiseppe, V.E.; Gusev, K.; Hallin, A.L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E.W.; Howard, S.; Howe, M.A.; Keeter, K.J.; Kidd, M.F.; Kochetov, O.; Konovalov, S.I.; Kouzes, R.T.; LaFerriere, B.D.; Leon, J.; Leviner, L.E.; Loach, J.C.; MacMullin, J.; MacMullin, S.; Martin, R.D.; Meijer, S.; Mertens, S.; Nomachi, M.; Orrell, J.L.; O'Shaughnessy, C.; Overman, N.R.; Phillips, D.G.; Poon, A.W.P.; Pushkin, K.; Radford, D.C.; Rager, J.; Rielage, K.; Robertson, R.G.H.; Romero-Romero, E.; Ronquest, M.C.; Schubert, A.G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K.J.; Snyder, N.; Suriano, A.M.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J.E.; Varner, R.L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B.R.; Wilkerson, J.F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A.R.; Yu, C.-H.; Yumatov, V.

    2015-01-01

    The Majorana Demonstrator will search for neutrinoless-double-beta decay (0???) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0??? experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0??? region of interest (ROI) of no more than 3 counts in the 0???-decay ROI per tonne of target isotope per year (cnts/(ROI-t-y)). The current status of the Demonstrator is discussed, as are plans for its completion.

  7. A Dark Matter Search with MALBEK

    SciTech Connect (OSTI)

    Giovanetti, G.K.; Abgrall, N.; Aguayo, E.; Avignone, F.T.; Barabash, A.S.; Bertrand, F.E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A.S.; Chan, Y-D.; Christofferson, C.D.; Combs, D.C.; Cuesta, C.; Detwiler, J.A.; Doe, P.J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S.R.; Fast, J.E.; Finnerty, P.; Fraenkle, F.M.; Galindo-Uribarri, A.; Goett, J.; Green, M.P.; Gruszko, J.; Guiseppe, V.E.; Gusev, K.; Hallin, A.L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E.W.; Howard, S.; Howe, M.A.; Keeter, K.J.; Kidd, M.F.; Kochetov, O.; Konovalov, S.I.; Kouzes, R.T.; LaFerriere, B.D.; Leon, J.; Leviner, L.E.; Loach, J.C.; MacMullin, J.; MacMullin, S.; Martin, R.D.; Meijer, S.; Mertens, S.; Nomachi, M.; Orrell, J.L.; O'Shaughnessy, C.; Overman, N.R.; Phillips, D.G.; Poon, A.W.P.; Pushkin, K.; Radford, D.C.; Rager, J.; Rielage, K.; Robertson, R.G.H.; Romero-Romero, E.; Ronquest, M.C.; Schubert, A.G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K.J.; Snyder, N.; Suriano, A.M.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J.E.; Varner, R.L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B.R.; Wilkerson, J.F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A.R.; Yu, C.-H.; Yumatov, V.

    2015-01-01

    The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of 76Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its subkeV energy threshold, this detector is sensitive to potential non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and explore the impact of slow surface event contamination when searching for a WIMP signal.

  8. Low background counting techniques at SNOLAB

    SciTech Connect (OSTI)

    Lawson, Ian; Cleveland, Bruce [SNOLAB, 1039 Regional Rd 24, Lively, ON P3Y 1N2 (Canada)] [SNOLAB, 1039 Regional Rd 24, Lively, ON P3Y 1N2 (Canada)

    2013-08-08

    Many of the experiments currently searching for dark matter, studying properties of neutrinos or searching for neutrinoless double beta decay require very low levels of radioactive backgrounds both in their own construction materials and in the surrounding environment. These low background levels are required so that the experiments can achieve the required sensitivities for their searches. SNOLAB has several facilities which are used to directly measure these radioactive backgrounds. This proceedings will describe SNOLAB's High Purity Germanium Detectors, one of which has been in continuous use for the past seven years measuring materials for many experiments in operation or under construction at SNOLAB. A description of the characterisation of SNOLAB's new germanium well detector will be presented. In addition, brief descriptions of SNOLAB's alpha-beta and electrostatic counters will be presented and a description of SNOLAB's future low background counting laboratory will be given.

  9. The MAJORANA DEMONSTRATOR for 0???: Current status and future plans

    SciTech Connect (OSTI)

    Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abgrall, N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Aguayo, E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Avignone, III, F. T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of South Carolina, Columbia, SC (United States); Barabash, A. S. [Institute for Theoretical and Experimental Physics, Moscow (Russia); Bertrand, F. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boswell, M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brudanin, V. [Joint Institute for Nuclear Research, Dubna (Russia); Busch, M. [Duke Univ., Durham, NC (United States); Triange Univ. Nuclear Lab., Durham, NC (United States); Byram, D. [Univ. of South Dakota, Vermillion, SD (United States); Caldwell, A. S. [South Dakota School of Mines and Technology, Rapid CIty, SD (United States); Chan, Y. -D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Christofferson, C. D. [South Dakota School of Mines and Technology, Rapid CIty, SD (United States); Combs, D. C. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Cuesta, C. [Univ. of Washington, Seattle, WA (United States); Detwiler, J. A. [Univ. of Washington, Seattle, WA (United States); Doe, P. J. [Univ. of Washington, Seattle, WA (United States); Efremenko, Yu. [Univ. of Tennessee, Knoxville, TN (United States); Egorov, V. [Joint Institute for Nuclear Research, Dubna (Russia); Ejiri, H. [Osaka Univ., Osaka (Japan); Elliott, S. R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fast, J. E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Finnerty, P. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Fraenkle, F. M. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giovanetti, G. K. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Goett, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gruszko, J. [Univ. of Washington, Seattle, WA (United States); Guiseppe, V. E. [Univ. of South Carolina, Columbia, SC (United States); Gusev, K. [Joint Institute for Nuclear Research, Dubna (Russia); Hallin, A. L. [Univ. of Alberta, Edmonton, AB (Canada); Hazama, R. [Osaka Univ., Osaka (Japan); Hegai, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); North Carolina State Univ., Raleigh, NC (United States); Henning, R. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Hoppe, E. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Howard, S. [South Dakota School of Mines and Technology, Rapid CIty, SD (United States); Howe, M. A. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Keeter, K. J. [Black Hills State Univ., Spearfish, SD (United States); Kidd, M. F. [Tennessee Tech Univ., Cookeville, TN (United States); Kochetov, O. [Joint Institute for Nuclear Research, Dubna (Russia); Konovalov, S. I. [Institute for Theoretical and Experimental Physics, Moscow (Russia); Kouzes, R. T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); LaFerriere, B. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leon, J. [Univ. of Washington, Seattle, WA (United States); Leviner, L. E. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Loach, J. C. [Shanghai Jiao Tong Univ., Shanghai (China); MacMullin, J. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); MacMullin, S. [Univ. of North Carolina, Chapel Hill, NC (United States)

    2015-01-01

    The Majorana Demonstrator will search for neutrinoless-double-beta decay (0???) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0??? experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0??? region of interest (ROI) of no more than 3 counts in the 0???-decay ROI per tonne of target isotope per year (cnts/(ROI-t-y)). The current status of the Demonstrator is discussed, as are plans for its completion.

  10. A dark matter search with MALBEK

    SciTech Connect (OSTI)

    Giovanetti, G. K. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Abgrall, N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Aguayo, E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Avignone, III, F. T. [Univ. of South Carolina, Columbia, SC (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Barabash, A. S. [Institute for Theoretical and Experimental Physics, Moscow (Russia); Bertrand, F. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boswell, M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brudanin, V. [Joint Institute for Nuclear Research, Dubna (Russia); Busch, M. [Duke Univ., Durham, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Byram, D. [Univ. of South Dakota, Vermillion, SD (United States); Caldwell, A. S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Chan, Y. -D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Christofferson, C. D. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Combs, D. C. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Cuesta, C. [Univ. of Washington, Seattle, WA (United States); Detwiler, J. A. [Univ. of Washington, Seattle, WA (United States); Doe, P. J. [Univ. of Washington, Seattle, WA (United States); Efremenko, Yu. [Univ. of Tennessee, Knoxville, TN (United States); Egorov, V. [Joint Institute for Nuclear Research, Dubna (Russia); Ejiri, H. [Osaka Univ., Osaka (Japan); Elliott, S. R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fast, J. E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Finnerty, P. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Fraenkle, F. M. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goett, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gruszko, J. [Univ. of Washington, Seattle, WA (United States); Guiseppe, V. E. [Univ. of South Carolina, Columbia, SC (United States); Gusev, K. [Joint Institute for Nuclear Research, Dubna (Russia); Hallin, A. L. [Univ. of Alberta, Edmonton, AB (Canada); Hazama, R. [Osaka Univ., Osaka (Japan); Hegai, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tuebingen Univ., Tuebingen (Germany); Henning, R. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Hoppe, E. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Howard, S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Howe, M. A. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Keeter, K. J. [Black Hills State Univ., Spearfish, SD (United States); Kidd, M. F. [Tennessee Tech Univ., Cookeville, TN (United States); Kochetov, O. [Joint Institute for Nuclear Research, Dubna (Russia); Konovalov, S. I. [Institute for Theoretical and Experimental Physics, Moscow (Russia); Kouzes, R. T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); LaFerriere, B. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leon, J. [Univ. of Washington, Seattle, WA (United States); Leviner, L. E. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Loach, J. C. [Shanghai Jiao Tong Univ., Shanghai (China); MacMullin, J. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); MacMullin, S. [Univ. of North Carolina, Chapel Hill, NC (United States)

    2015-01-01

    The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of ??Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its sub-keV energy threshold, this detector is sensitive to potential non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and explore the impact of slow surface event contamination when searching for a WIMP signal.

  11. The MAJORANA DEMONSTRATOR for 0???: Current status and future plans

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Green, M. P.; Abgrall, N.; Aguayo, E.; Avignone, III, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; et al

    2015-01-01

    The Majorana Demonstrator will search for neutrinoless-double-beta decay (0???) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0??? experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0??? region of interest (ROI) of nomore »more than 3 counts in the 0???-decay ROI per tonne of target isotope per year (cnts/(ROI-t-y)). The current status of the Demonstrator is discussed, as are plans for its completion.« less

  12. The Majorana Demonstrator for 0vBB: Current Status and Future Plans

    SciTech Connect (OSTI)

    Green, Matthew P; Avignone, F. T.; Galindo-Uribarri, Alfredo {nmn}; Radford, David C; Romero-Romero, Elisa; Varner Jr, Robert L; White, Brandon R; Wilkerson, J. F.; Majorana,

    2015-01-01

    The Majorana Demonstrator will search for neutrinoless-double-beta decay (0 ) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0 experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0 region of interest (ROI) of no more than 3cnts/(ROI-t-y). The current status of the Demonstrator is discussed, as are plans for its completion.

  13. Search for neutrinoless double-beta decay of Ge-76 with GERDA

    E-Print Network [OSTI]

    Karl-Tasso Knoepfle

    2008-10-17

    GERDA, the GERmanium Detector Array experiment, is a new double beta-decay experiment which is currently under construction in the INFN National Gran Sasso Laboratory (LNGS), Italy. It is implementing a new shielding concept by operating bare Ge diodes - enriched in Ge-76 - in high purity liquid argon supplemented by a water shield. The aim of GERDA is to verify or refute the recent claim of discovery, and, in a second phase, to achieve a two orders of magnitude lower background index than recent experiments. The paper discusses motivation, physics reach, design and status of construction of GERDA, and presents some R&D results.

  14. Low Background Signal Readout Electronics for the MAJORANA DEMONSTRATOR

    E-Print Network [OSTI]

    I. Guinn; N. Abgrall; I. J. Arnquist; F. T. Avignone III; C. X. Baldenegro-Barrera; A. S. Barabash; F. E. Bertrand; A. W. Bradley; V. Brudanin; M. Busch; M. Buuck; D. Byram; A. S. Caldwell; Y-D. Chan; C. D. Christofferson; C. Cuesta; J. A. Detwiler; Yu. Efremenko; H. Ejiri; S. R. Elliott; A. Galindo-Uribarri; T. Gilliss; G. K. Giovanetti; J. Goett; M. P. Green; J. Gruszko; V. E. Guiseppe; R. Henning; E. W. Hoppe; S. Howard; M. A. Howe; B. R. Jasinski; K. J. Keeter; M. F. Kidd; S. I. Konovalov; R. T. Kouzes; B. D. LaFerriere; J. Leon; J. MacMullin; R. D. Martin; S. J. Meijer; S. Mertens; J. L. Orrell; C. O'Shaughnessy; A. W. P. Poon; D. C. Radford; J. Rager; K. Rielage; R. G. H. Robertson; E. Romero-Romero; B. Shanks; M. Shirchenko; N. Snyder; A. M. Suriano; D. Tedeschi; J. E. Trimble; R. L. Varner; S. Vasilyev; K. Vetter; K. Vorren; B. R. White; J. F. Wilkerson; C. Wiseman; W. Xu; E. Yakushev; C. -H. Yu; V. Yumatov; I. Zhitnikov

    2015-06-13

    The MAJORANA Collaboration will seek neutrinoless double beta decay (0nbb) in 76Ge using isotopically enriched p-type point contact (PPC) high purity Germanium (HPGe) detectors. A tonne-scale array of HPGe detectors would require background levels below 1 count/ROI-tonne-year in the 4 keV region of interest (ROI) around the 2039 keV Q-value of the decay. In order to demonstrate the feasibility of such an experiment, the MAJORANA DEMONSTRATOR, a 40 kg HPGe detector array, is being constructed with a background goal of design used to construct signal readout electronics with low enough backgrounds for the MAJORANA DEMONSTRATOR.

  15. Low Background Signal Readout Electronics for the MAJORANA DEMONSTRATOR

    E-Print Network [OSTI]

    Guinn, I; Arnquist, I J; Avignone, F T; Baldenegro-Barrera, C X; Barabash, A S; Bertrand, F E; Bradley, A W; Brudanin, V; Busch, M; Buuck, M; Byram, D; Caldwell, A S; Chan, Y-D; Christofferson, C D; Cuesta, C; Detwiler, J A; Efremenko, Yu; Ejiri, H; Elliott, S R; Galindo-Uribarri, A; Gilliss, T; Giovanetti, G K; Goett, J; Green, M P; Gruszko, J; Guiseppe, V E; Henning, R; Hoppe, E W; Howard, S; Howe, M A; Jasinski, B R; Keeter, K J; Kidd, M F; Konovalov, S I; Kouzes, R T; LaFerriere, B D; Leon, J; MacMullin, J; Martin, R D; Meijer, S J; Mertens, S; Orrell, J L; O'Shaughnessy, C; Poon, A W P; Radford, D C; Rager, J; Rielage, K; Robertson, R G H; Romero-Romero, E; Shanks, B; Shirchenko, M; Snyder, N; Suriano, A M; Tedeschi, D; Trimble, J E; Varner, R L; Vasilyev, S; Vetter, K; Vorren, K; White, B R; Wilkerson, J F; Wiseman, C; Xu, W; Yakushev, E; Yu, C -H; Yumatov, V; Zhitnikov, I

    2015-01-01

    The MAJORANA Collaboration will seek neutrinoless double beta decay (0nbb) in 76Ge using isotopically enriched p-type point contact (PPC) high purity Germanium (HPGe) detectors. A tonne-scale array of HPGe detectors would require background levels below 1 count/ROI-tonne-year in the 4 keV region of interest (ROI) around the 2039 keV Q-value of the decay. In order to demonstrate the feasibility of such an experiment, the MAJORANA DEMONSTRATOR, a 40 kg HPGe detector array, is being constructed with a background goal of design used to construct signal readout electronics with low enough backgrounds for the MAJORANA DEMONSTRATOR.

  16. Monte Carlo Comparisons to a Cryogenic Dark Matter Search Detector with Low Transition-Edge-Sensor Transition Temperature

    SciTech Connect (OSTI)

    Leman, S.W.; McCarthy, K.A.; /MIT, MKI; Brink, P.L.; Cabrera, B.; Cherry, M.; /Stanford U., Phys. Dept.; Silva, E.Do Couto E; /SLAC; Figueroa-Feliciano, E.; /MIT, MKI; Kim, P.; /SLAC; Mirabolfathi, N.; /UC, Berkeley; Pyle, M.; /Stanford U., Phys. Dept.; Resch, R.; /SLAC; Sadoulet, B.; Serfass, B.; Sundqvist, K.M.; /UC, Berkeley; Tomada, A.; /Stanford U., Phys. Dept.; Young, B.A.; /Santa Clara U.

    2012-06-05

    We present results on phonon quasidiffusion and Transition Edge Sensor (TES) studies in a large, 3-inch diameter, 1-inch thick [100] high purity germanium crystal, cooled to 50 mK in the vacuum of a dilution refrigerator, and exposed with 59.5 keV gamma-rays from an Am-241 calibration source. We compare calibration data with results from a Monte Carlo which includes phonon quasidiffusion and the generation of phonons created by charge carriers as they are drifted across the detector by ionization readout channels. The phonon energy is then parsed into TES based phonon readout channels and input into a TES simulator.

  17. Search for CPT-odd decays of positronium

    SciTech Connect (OSTI)

    Vetter, Paul A.; Freedman, Stuart J.

    2003-07-11

    We have limited a CPT-violating correlation in annihilationsof polarized ortho-positronium. We searched for an asymmetry in thetriple correlations dot k1 cross k2, where k1 and k2 are the two largestphoton momenta, and s is the spin of the positronium. Using theGammasphere array of Compton-suppressed high-purity germanium detectors,we detected 2.65e7 events of ortho-Ps annihila tion. The amplitude of aCPT-violating asymmetry in the data set is found to be 0.0026 plus orminus 0.0031, a factor of 6 smaller than previousexperiments.

  18. On the Effect of Local Grain-Boundary Chemistry on the Macroscopic Mechanical Properties of a High Purity Y2O3-Al2O3-Containing Silicon Nitride Ceramic

    E-Print Network [OSTI]

    Ritchie, Robert

    of oxidizing heat treatments and sintering additives, was found to result in a transition in fracture mechanism-sintering heat treatments have invariably been found to improve the strength, creep and toughness properties the mechanical properties, in terms of the effect of (i) post-sintering heat treatments and (ii) slight

  19. Majorana Electroformed Copper Mechanical Analysis

    SciTech Connect (OSTI)

    Overman, Nicole R.; Overman, Cory T.; Kafentzis, Tyler A.; Edwards, Danny J.; Hoppe, Eric W.

    2012-04-30

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay. The DEMONSTRATOR will utilize ultra high purity electroformed copper for a variety of detector components and shielding. A preliminary mechanical evaluation was performed on the Majorana prototype electroformed copper material. Several samples were removed from a variety of positions on the mandrel. Tensile testing, optical metallography, scanning electron microscopy, and hardness testing were conducted to evaluate mechanical response. Analyses carried out on the Majorana prototype copper to this point show consistent mechanical response from a variety of test locations. Evaluation shows the copper meets or exceeds the design specifications.

  20. Activation Layer Stabilization of High Polarization Photocathodes in Sub-Optimal RF Gun Environments

    SciTech Connect (OSTI)

    Gregory A. Mulhollan

    2010-11-16

    Specific activation recipes for bulk, 100 nm thick MBE grown and high polarization III-V photocathode material have been developed which mitigate the effects of exposure to background gasses. Lifetime data using four representative gasses were acquired for bulk GaAs, 100 nm unstrained GaAs and strained superlattice GaAs/GaAsP, all activated both with Cs and then Cs and Li (bi-alkali). Each photoemitter showed marked resilience improvement when activated using the bi-alkali recipe compared to the standard single alkali recipe. A dual alkali activation system at SLAC was constructed, baked and commissioned with the purpose of performing spin-polarization measurements on electrons emitted from the bi-alkali activated surfaces. An end station at SSRL was configured with the required sources for energy resolved photoemission measurements on the bi-alkali activated and CO2 dosed surfaces. The bi-alkali recipes were successfully implemented at SLAC/SSRL. Measurements at SLAC of the photoelectron spin-polarization from the modified activation surface showed no sign of a change in value compared to the standard activated material, i.e., no ill effects. Analysis of photoemission data indicates that the addition of Li to the activation layer results in a multi-layer structure. The presence of Li in the activation layer also acts as an inhibitor to CO2 absorption, hence better lifetimes in worse vacuum were achieved. The bi-alkali activation has been tested on O2 activated GaAs for comparison with NF3 activated surfaces. Comparable resilience to CO2 exposure was achieved for the O2 activated surface. An RF PECVD amorphous silicon growth system was modified to allow high temperature heat cleaning of GaAs substrates prior to film deposition. Growth versus thickness data were collected. Very thin amorphous silicon germanium layers were optimized to exhibit good behavior as an electron emitter. Growth of the amorphous silicon germanium films on the above substrates was fine tuned with respect to time and power to moderate plasma damage to the photo-generating layer. Auger electron spectroscopy was used to analyze the composition and thickness of the emitter layers. AFM studies showed conformal growth on the GaAs substrates. Measurements at SLAC on the photoemitted electrons from high polarization substrates coated with amorphous silicon germanium indicated an ~10% relative drop in spin-polarization at the wavelength corresponding to the maximum spin-polarization when compared to the uncoated material,

  1. High specific activity silicon-32

    DOE Patents [OSTI]

    Phillips, Dennis R. (Los Alamos, NM); Brzezinski, Mark A. (Santa Barbara, CA)

    1996-01-01

    A process for preparation of silicon-32 is provided and includes contacting an irradiated potassium chloride target, including spallation products from a prior irradiation, with sufficient water, hydrochloric acid or potassium hydroxide to form a solution, filtering the solution, adjusting pH of the solution to from about 5.5 to about 7.5, admixing sufficient molybdate-reagent to the solution to adjust the pH of the solution to about 1.5 and to form a silicon-molybdate complex, contacting the solution including the silicon-molybdate complex with a dextran-based material, washing the dextran-based material to remove residual contaminants such as sodium-22, separating the silicon-molybdate complex from the dextran-based material as another solution, adding sufficient hydrochloric acid and hydrogen peroxide to the solution to prevent reformation of the silicon-molybdate complex and to yield an oxidization state of the molybdate adapted for subsequent separation by an anion exchange material, contacting the solution with an anion exchange material whereby the molybdate is retained by the anion exchange material and the silicon remains in solution, and optionally adding sufficient alkali metal hydroxide to adjust the pH of the solution to about 12 to 13. Additionally, a high specific activity silicon-32 product having a high purity is provided.

  2. High temperature support apparatus and method of use for casting materials

    DOE Patents [OSTI]

    Clark, Roger F; Cliber, James A; Stoddard, Nathan G; Gerber, Jesse I; Roberts, Raymond J; Wilmerton, Mark A

    2015-02-10

    This invention relates to a system and a method of use for large ceramic member support and manipulation at elevated temperatures in non-oxidizing atmospheres, such as using carbon-carbon composite materials for producing high purity silicon in the manufacture of solar modules. The high temperature apparatus of this invention includes one or more support ribs, one or more cross braces in combination with the one or more support ribs, and a shaped support liner positionable upon the one or more support ribs and the one or more cross braces.

  3. UK low-background infrastructure for delivering SuperNEMO

    E-Print Network [OSTI]

    Liu, Xin Ran

    2015-01-01

    SuperNEMO is a next generation neutrinoless double beta decay experiment with a design capability to reach a half-life sensitivity of $10^{26}$ years corresponding to an effective Majorana neutrino mass of $\\langle m_{\\beta\\beta} \\rangle$ $<$ 50 - 100 meV. To achieve this sensitivity, stringent radio-purity requirements are imposed resulting in an equally stringent screening programme. Dedicated facilities have been established in the UK for screening and selection of detector construction materials. Gamma ray spectroscopy using high-purity germanium (HPGe) detectors has been the standard method for the measurement of material contamination. A low-background facility has been established at Boulby Underground Laboratory. The first results from the 2 current HPGe detector are shown. Radon is one of the most critical backgrounds for SuperNEMO and most other low background experiments. It can enter the detector either through diffusion, contamination during construction or emanation from the detector material...

  4. Study of thermal neutron capture gamma rays using a lithium-drifted germanium spectrometer / [by] Victor John Orphan [and] Norman C. Rasmussen

    E-Print Network [OSTI]

    Orphan, V. J.

    1967-01-01

    A gamma-ray spectrometer, using a 30 cc coaxial Ge(Li) detector, which can be operated as a pair spectrometer at high energies and in the Compton suppression mode at low energies provides an effective means of obtaining ...

  5. Al{sub 2}O{sub 3}/GeO{sub x} gate stack on germanium substrate fabricated by in situ cycling ozone oxidation method

    SciTech Connect (OSTI)

    Yang, Xu; Zeng, Zhen-Hua [Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanjing 210096 (China); Microwave Device and IC Department, Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); Wang, Sheng-Kai, E-mail: wangshengkai@ime.ac.cn, E-mail: xzhang62@aliyun.com, E-mail: liuhonggang@ime.ac.cn; Sun, Bing; Zhao, Wei; Chang, Hu-Dong; Liu, Honggang, E-mail: wangshengkai@ime.ac.cn, E-mail: xzhang62@aliyun.com, E-mail: liuhonggang@ime.ac.cn [Microwave Device and IC Department, Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); Zhang, Xiong, E-mail: wangshengkai@ime.ac.cn, E-mail: xzhang62@aliyun.com, E-mail: liuhonggang@ime.ac.cn [Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanjing 210096 (China)

    2014-09-01

    Al{sub 2}O{sub 3}/GeO{sub x}/Ge gate stack fabricated by an in situ cycling ozone oxidation (COO) method in the atomic layer deposition (ALD) system at low temperature is systematically investigated. Excellent electrical characteristics such as minimum interface trap density as low as 1.9?×?10{sup 11?}cm{sup ?2?}eV{sup ?1} have been obtained by COO treatment. The impact of COO treatment against the band alignment of Al{sub 2}O{sub 3} with respect to Ge is studied by x-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry (SE). Based on both XPS and SE studies, the origin of gate leakage in the ALD-Al{sub 2}O{sub 3} is attributed to the sub-gap states, which may be correlated to the OH-related groups in Al{sub 2}O{sub 3} network. It is demonstrated that the COO method is effective in repairing the OH-related defects in high-k dielectrics as well as forming superior high-k/Ge interface for high performance Ge MOS devices.

  6. High-efficiency solar cell and method for fabrication

    DOE Patents [OSTI]

    Hou, Hong Q. (Albuquerque, NM); Reinhardt, Kitt C. (Albuquerque, NM)

    1999-01-01

    A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD).

  7. High-efficiency solar cell and method for fabrication

    DOE Patents [OSTI]

    Hou, H.Q.; Reinhardt, K.C.

    1999-08-31

    A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD). 4 figs.

  8. Interfacial band alignment and structural properties of nanoscale TiO{sub 2} thin films for integration with epitaxial crystallographic oriented germanium

    SciTech Connect (OSTI)

    Jain, N.; Zhu, Y.; Hudait, M. K., E-mail: mantu.hudait@vt.edu [Advanced Devices and Sustainable Energy Laboratory (ADSEL), Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Maurya, D.; Varghese, R.; Priya, S. [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2014-01-14

    We have investigated the structural and band alignment properties of nanoscale titanium dioxide (TiO{sub 2}) thin films deposited on epitaxial crystallographic oriented Ge layers grown on (100), (110), and (111)A GaAs substrates by molecular beam epitaxy. The TiO{sub 2} thin films deposited at low temperature by physical vapor deposition were found to be amorphous in nature, and high-resolution transmission electron microscopy confirmed a sharp heterointerface between the TiO{sub 2} thin film and the epitaxially grown Ge with no traceable interfacial layer. A comprehensive assessment on the effect of substrate orientation on the band alignment at the TiO{sub 2}/Ge heterointerface is presented by utilizing x-ray photoelectron spectroscopy and spectroscopic ellipsometry. A band-gap of 3.33?±?0.02?eV was determined for the amorphous TiO{sub 2} thin film from the Tauc plot. Irrespective of the crystallographic orientation of the epitaxial Ge layer, a sufficient valence band-offset of greater than 2?eV was obtained at the TiO{sub 2}/Ge heterointerface while the corresponding conduction band-offsets for the aforementioned TiO{sub 2}/Ge system were found to be smaller than 1?eV. A comparative assessment on the effect of Ge substrate orientation revealed a valence band-offset relation of ?E{sub V}(100)?>??E{sub V}(111)?>??E{sub V}(110) and a conduction band-offset relation of ?E{sub C}(110) >??E{sub C}(111)?>??E{sub C}(100). These band-offset parameters are of critical importance and will provide key insight for the design and performance analysis of TiO{sub 2} for potential high-? dielectric integration and for future metal-insulator-semiconductor contact applications with next generation of Ge based metal-oxide field-effect transistors.

  9. Assessing the benefits of OHER (Office of Health and Environmental Research) research: Three case studies

    SciTech Connect (OSTI)

    Nesse, R.J.; Callaway, J.M.; Englin, J.E.; Klan, M.S.; Nicholls, A.K.; Serot, D.E.

    1987-09-01

    This research was undertaken to estimate the societal benefits and costs of selected past research performed for the Office of Health and Environmental Research (OHER) of the US Department of Energy (DOE). Three case studies of representative OHER and DOE research were performed. One of these, the acid rain case study, includes research conducted elsewhere in DOE. The other two cases were the OHER marine research program and the development of high-purity germanium that is used in radiation detectors. The acid rain case study looked at the research benefits and costs of furnace sorbent injection and duct injection, technologies that might reduce acid deposition precursors. Both appear to show benefits in excess of costs. We examined in detail one of the OHER marine research program's accomplishments - the increase in environmental information used by the Outer Continental Shelf leasing program to manage bidding for off-shore oil drilling. The results of an econometric model show that environmental information of the type supported by OHER is unequivocally linked to government and industry leasing decisions. The germanium case study indicated that the benefits of germanium radiation detectors were significant.

  10. Production of high specific activity silicon-32

    DOE Patents [OSTI]

    Phillips, Dennis R. (Los Alamos, NM); Brzezinski, Mark A. (Santa Barbara, CA)

    1994-01-01

    A process for preparation of silicon-32 is provide and includes contacting an irradiated potassium chloride target, including spallation products from a prior irradiation, with sufficient water, hydrochloric acid or potassium hydroxide to form a solution, filtering the solution, adjusting pH of the solution to from about 5.5 to about 7.5, admixing sufficient molybdate-reagent to the solution to adjust the pH of the solution to about 1.5 and to form a silicon-molybdate complex, contacting the solution including the silicon-molybdate complex with a dextran-based material, washing the dextran-based material to remove residual contaminants such as sodium-22, separating the silicon-molybdate complex from the dextran-based material as another solution, adding sufficient hydrochloric acid and hydrogen peroxide to the solution to prevent reformation of the silicon-molybdate complex and to yield an oxidization state of the molybdate adapted for subsequent separation by an anion exchange material, contacting the solution with an anion exchange material whereby the molybdate is retained by the anion exchange material and the silicon remains in solution, and optionally adding sufficient alkali metal hydroxide to adjust the pH of the solution to about 12 to 13. Additionally, a high specific activity silicon-32 product having a high purity is provided.

  11. Grain boundary depletion and migration during selective oxidation of Cr in a Ni-5Cr binary alloy exposed to high-temperature hydrogenated water

    SciTech Connect (OSTI)

    Schreiber, Daniel K.; Olszta, Matthew J.; Bruemmer, Stephen M.

    2014-10-01

    High-resolution microscopy of a high-purity Ni-5Cr alloy exposed to 360°C hydrogenated water reveals intergranular selective oxidation of Cr accompanied by local Cr depletion and diffusion-induced grain boundary migration (DIGM). The corrosion-product oxide consists of a porous, interconnected network of Cr2O3 platelets with no further O ingress into the metal ahead. Extensive grain boundary depletion of Cr (to <0.05at.%) is observed typically 20–100 nm wide as a result of DIGM and reaching depths of many micrometers beyond the oxidation front.

  12. Complex crystallization dynamics in amorphous germanium observed...

    Office of Scientific and Technical Information (OSTI)

    Date: 2013-02-01 OSTI Identifier: 1102279 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal Volume: 87; Journal...

  13. Electrical characterization of germanium-silicon alloy 

    E-Print Network [OSTI]

    Kishore, Kumar P.

    1994-01-01

    . The fabrication procedure involved sputter deposition of silicon dioxide, oxide patterning, deposition of aluminum metal and metal patterning. Each test structure was square-shaped and consisted of eight sets of peripheral metal contacts. The results...

  14. Germanium Oxide Nanoparticlesfor Superior Battery Electrodes - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Low LETUseful Links Useful Links: TheGerard*

  15. High-quality photonic crystals with a nearly complete band gap obtained by direct inversion of woodpile templates with titanium dioxide

    E-Print Network [OSTI]

    Marichy, Catherine; Froufe-Pérez, Luis S; Scheffold, Frank

    2015-01-01

    Photonic crystal materials are based on a periodic modulation of the dielectric constant on length scales comparable to the wavelength of light. These materials can exhibit photonic band gaps; frequency regions for which the propagation of electromagnetic radiation is forbidden due to the depletion of the density of states. In order to exhibit a full band gap, 3D PCs must present a threshold refractive index contrast that depends on the crystal structure. In the case of the so-called woodpile photonic crystals this threshold is comparably low, approximately 1.9 for the direct structure. Therefore direct or inverted woodpiles made of high refractive index materials like silicon, germanium or titanium dioxide are sought after. Here we show that, by combining multiphoton lithography and atomic layer deposition, we can achieve a direct inversion of polymer templates into TiO$_{2}$ based photonic crystals. The obtained structures show remarkable optical properties in the near-infrared region with almost perfect sp...

  16. Physical and mechanical properties of single and large crystal high-RRR niobium

    SciTech Connect (OSTI)

    Ganapati Myneni

    2005-07-10

    High RRR bulk niobium SRF cavities are the building blocks of the latest and future particle accelerators, free electron lasers (FEL's) and energy recovery linacs (ERL's.). These cavities are fabricated from high purity (RRR) poly crystalline niobium sheets via deep drawing, e-beam welding and surface treatment to obtain high accelerating gradients and quality factors. However, the starting bulk RRR niobium properties are not yet optimized with respect to both cost reduction and achievement of ultimate performance. A major limitation in achieving the highest performance can possibly be attributed to imperfections at or near the grain boundaries. Recently, at Jefferson Lab single/large grain RRR niobium cavities are developed using customized RRR ingots with optimized amounts of impurities such as Tantalum and minimizing the interstitial contents (O, C, N and H).

  17. Recent Observation of Hydrogen-Induced Cracking of High-Strength Steels

    SciTech Connect (OSTI)

    McMahon, Jr, C J; Liu, Xinyu; Kameda, Jun; Morgan, Michael J

    2008-09-14

    The present progress report shows that the ultra-high-strength 4340-type steel, even if ideally pure, cannot safely be used for service in a hydrogen environment. Some of the strength must be given up in favor of more toughness, which can be achieved by reducing the carbon content and increasing the nickel content. The 5%NiCrMoV steel with about 0.1% carbon shows promise in this regard, especially in an aqueous environment and in hydrogen at around atmospheric pressure. However, we have not yet achieved a purity level high enough to establish the baseline behavior of an ideally pure version of this steel in high-pressure hydrogen.

  18. Guiding of low-energy electrons by highly ordered Al{sub 2}O{sub 3} nanocapillaries

    SciTech Connect (OSTI)

    Milosavljevic, A. R.; Vikor, Gy.; Pesic, Z. D.; Kolarz, P.; Sevic, D.; Marinkovic, B. P.; Matefi-Tempfli, S.; Matefi-Tempfli, M.; Piraux, L.

    2007-03-15

    We report an experimental study of guided transmission of low-energy (200-350 eV) electrons through highly ordered Al{sub 2}O{sub 3} nanocapillaries with large aspect ratio (140 nm diameter and 15 {mu}m length). The nanochannel array was prepared using self-ordering phenomena during a two-step anodization process of a high-purity aluminum foil. The experimental results clearly show the existence of the guiding effect, as found for highly charged ions. The guiding of the electron beam was observed for tilt angles up to 12 degree sign . As seen for highly charged ions, the guiding efficiency increases with decreasing electron incident energy. The transmission efficiency appeared to be significantly lower than observed for highly charged ions and, moreover, the intensity of transmitted electrons significantly decreases with decreasing impact energy.

  19. High PRF high current switch

    DOE Patents [OSTI]

    Moran, Stuart L. (Fredericksburg, VA); Hutcherson, R. Kenneth (College Park, MD)

    1990-03-27

    A triggerable, high voltage, high current, spark gap switch for use in pu power systems. The device comprises a pair of electrodes in a high pressure hydrogen environment that is triggered by introducing an arc between one electrode and a trigger pin. Unusually high repetition rates may be obtained by undervolting the switch, i.e., operating the trigger at voltages much below the self-breakdown voltage of the device.

  20. 2011 Fall : Highly Distinguished Honors Highly Distinguished

    E-Print Network [OSTI]

    Kunkle, Tom

    Distinguished Beidler Katilyn V. Highly Distinguished Belanger Brett Russell Highly Distinguished Bell Lauren Ashley Highly Distinguished Bennett Caitlin Renee Highly Distinguished Berdusco Ann Marie Highly Highly Distinguished Bertel Jeffrey Robert Highly Distinguished Bettendorf Caitlin Marie Highly

  1. High speed, multi-channel, user programmable digital data acquisition system.

    SciTech Connect (OSTI)

    Sabourov, Konstantin; Hennig, Wolfgang; Walby, Mark

    2013-11-18

    As applications for radiation detection become more demanding, and in turn improvements are made in the technology of radiation detection, there is a need for high speed digital detector readout electronics matching these improvements. Specifically, full control over the on-line processing resources of modern digital electronics is desirable so that researchers can develop custom algorithms for special applications.In the proposed effort, the 500 MHz digital readout electronics previously developed by our company will be redesigned to allow user access to the on-line processing resources. In Phase I, the division of online processing into vendor and user firmware sections has been studied on existing hardware. In Phase II, the hardware will be upgraded to better facilitate the division, and the firmware will be restructured into a robust vendor logic block (providing standard functions such as host I/O, on-board memory I/O, energy computation, MCA spectra, timestamps, waveform capture, run statistics, and triggering and timing) and a user logic block for custom algorithms (with templates and examples for frequently used functions). Investigating several options to divide online processing, it was determined that the most promising approach is to “partition” a single FPGA integrated circuit into a vendor and user section, which is supported in newer devices. The analog front end of the existing electronics proved suitable for most applications, in particular high rate measurements with germanium detectors. The design architecture for new electronics was developed, combining one of the new FPGA device with the analog front end.

  2. Upgrade of Beam Energy Measurement System at BEPC-II

    E-Print Network [OSTI]

    Jian-Yong Zhang; Xiao Cai; Xiao-Hu Mo; Di-Zhou Guo; Jian-Li Wang; Bai-Qi Liu; M. N. Achasov; A. A. Krasnov; N. Yu. Muchnoi; E. E. Pyata; E. V. Mamoshkina; F. A. Harris

    2015-10-28

    The beam energy measurement system is of great importance and profit for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. Many advanced techniques and precise instruments are employed to realize the highly accurate measurement of positron/electron beam energy. During five year's running period, in order to meet the requirement of data taking and improve the capacity of measurement itself, the upgradation of system is continued, which involve the component reformation of laser and optics subsystem, replacement of view-port of the laser to vacuum insertion subsystem, the purchase of electric cooling system for high purity germanium detector, and the improvement of data acquisition and processing subsystem. The upgrading of system guarantees the smooth and efficient measuring of beam energy at BEPC-II and accommodates the accurate offline energy values for further physics analysis at BES-III.

  3. Upgrade of Beam Energy Measurement System at BEPC-II

    E-Print Network [OSTI]

    Zhang, Jian-Yong; Mo, Xiao-Hu; Guo, Di-Zhou; Wang, Jian-Li; Liu, Bai-Qi; Achasov, M N; Krasnov, A A; Muchnoi, N Yu; Pyata, E E; Mamoshkina, E V; Harris, F A

    2015-01-01

    The beam energy measurement system is of great importance and profit for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. Many advanced techniques and precise instruments are employed to realize the highly accurate measurement of positron/electron beam energy. During five year's running period, in order to meet the requirement of data taking and improve the capacity of measurement itself, the upgradation of system is continued, which involve the component reformation of laser and optics subsystem, replacement of view-port of the laser to vacuum insertion subsystem, the purchase of electric cooling system for high purity germanium detector, and the improvement of data acquisition and processing subsystem. The upgrading of system guarantees the smooth and efficient measuring of beam energy at BEPC-II and accommodates the accurate offline energy values for further physics analysis at BES-III.

  4. AGATA - Advanced Gamma Tracking Array

    E-Print Network [OSTI]

    S. Akkoyun; A. Algora; B. Alikhani; F. Ameil; G. de Angelis; L. Arnold; A. Astier; A. Ataç; Y. Aubert; C. Aufranc; A. Austin; S. Aydin; F. Azaiez; S. Badoer; D. L. Balabanski; D. Barrientos; G. Baulieu; R. Baumann; D. Bazzacco; F. A. Beck; T. Beck; P. Bednarczyk; M. Bellato; M. A. Bentley; G. Benzoni; R. Berthier; L. Berti; R. Beunard; G. Lo Bianco; B. Birkenbach; P. G. Bizzeti; A. M. Bizzeti-Sona; F. Le Blanc; J. M. Blasco; N. Blasi; D. Bloor; C. Boiano; M. Borsato; D. Bortolato; A. J. Boston; H. C. Boston; P. Bourgault; P. Boutachkov; A. Bouty; A. Bracco; S. Brambilla; I. P. Brawn; A. Brondi; S. Broussard; B. Bruyneel; D. Bucurescu; I. Burrows; A. Bürger; S. Cabaret; B. Cahan; E. Calore; F. Camera; A. Capsoni; F. Carrió; G. Casati; M. Castoldi; B. Cederwall; J. -L. Cercus; V. Chambert; M. El Chambit; R. Chapman; L. Charles; J. Chavas; E. Clément; P. Cocconi; S. Coelli; P. J. Coleman-Smith; A. Colombo; S. Colosimo; C. Commeaux; D. Conventi; R. J. Cooper; A. Corsi; A. Cortesi; L. Costa; F. C. L. Crespi; J. R. Cresswell; D. M. Cullen; D. Curien; A. Czermak; D. Delbourg; R. Depalo; T. Descombes; P. Désesquelles; P. Detistov; C. Diarra; F. Didierjean; M. R. Dimmock; Q. T. Doan; C. Domingo-Pardo; M. Doncel; F. Dorangeville; N. Dosme; Y. Drouen; G. Duchêne; B. Dulny; J. Eberth; P. Edelbruck; J. Egea; T. Engert; M. N. Erduran; S. Ertürk; C. Fanin; S. Fantinel; E. Farnea; T. Faul; M. Filliger; F. Filmer; Ch. Finck; G. de France; A. Gadea; W. Gast; A. Geraci; J. Gerl; R. Gernhäuser; A. Giannatiempo; A. Giaz; L. Gibelin; A. Givechev; N. Goel; V. González; A. Gottardo; X. Grave; J. Gr?bosz; R. Griffiths; A. N. Grint; P. Gros; L. Guevara; M. Gulmini; A. Görgen; H. T. M. Ha; T. Habermann; L. J. Harkness; H. Harroch; K. Hauschild; C. He; A. Hernández-Prieto; B. Hervieu; H. Hess; T. Hüyük; E. Ince; R. Isocrate; G. Jaworski; A. Johnson; J. Jolie; P. Jones; B. Jonson; P. Joshi; D. S. Judson; A. Jungclaus; M. Kaci; N. Karkour; M. Karolak; A. Ka?ka?; M. Kebbiri; R. S. Kempley; A. Khaplanov; S. Klupp; M. Kogimtzis; I. Kojouharov; A. Korichi; W. Korten; Th. Kröll; R. Krücken; N. Kurz; B. Y. Ky; M. Labiche; X. Lafay; L. Lavergne; I. H. Lazarus; S. Leboutelier; F. Lefebvre; E. Legay; L. Legeard; F. Lelli; S. M. Lenzi; S. Leoni; A. Lermitage; D. Lersch; J. Leske; S. C. Letts; S. Lhenoret; R. M. Lieder; D. Linget; J. Ljungvall; A. Lopez-Martens; A. Lotodé; S. Lunardi; A. Maj; J. van der Marel; Y. Mariette; N. Marginean; R. Marginean; G. Maron; A. R. Mather; W. M?czy?ski; V. Mendéz; P. Medina; B. Melon; R. Menegazzo; D. Mengoni; E. Merchan; L. Mihailescu; C. Michelagnoli; J. Mierzejewski; L. Milechina; B. Million; K. Mitev; P. Molini; D. Montanari; S. Moon; F. Morbiducci; R. Moro; P. S. Morrall; O. Möller; A. Nannini; D. R. Napoli; L. Nelson; M. Nespolo; V. L. Ngo; M. Nicoletto; R. Nicolini; Y. Le Noa; P. J. Nolan; M. Norman; J. Nyberg; A. Obertelli; A. Olariu; R. Orlandi; D. C. Oxley; C. Özben; M. Ozille; C. Oziol; E. Pachoud; M. Palacz; J. Palin; J. Pancin; C. Parisel; P. Pariset; G. Pascovici; R. Peghin; L. Pellegri; A. Perego; S. Perrier; M. Petcu; P. Petkov; C. Petrache; E. Pierre; N. Pietralla; S. Pietri; M. Pignanelli; I. Piqueras; Z. Podolyak; P. Le Pouhalec; J. Pouthas; D. Pugnére; V. F. E. Pucknell; A. Pullia; B. Quintana; R. Raine; G. Rainovski; L. Ramina; G. Rampazzo; G. La Rana; M. Rebeschini; F. Recchia; N. Redon; M. Reese; P. Reiter; P. H. Regan; S. Riboldi; M. Richer; M. Rigato; S. Rigby; G. Ripamonti; A. P. Robinson; J. Robin; J. Roccaz; J. -A. Ropert; B. Rossé; C. Rossi Alvarez; D. Rosso; B. Rubio; D. Rudolph; F. Saillant; E. ?ahin; F. Salomon; M. -D. Salsac; J. Salt; G. Salvato; J. Sampson; E. Sanchis; C. Santos; H. Schaffner; M. Schlarb; D. P. Scraggs; D. Seddon; M. ?enyi?it; M. -H. Sigward; G. Simpson; J. Simpson; M. Slee; J. F. Smith; P. Sona; B. Sowicki; P. Spolaore; C. Stahl; T. Stanios; E. Stefanova; O. Stézowski; J. Strachan; G. Suliman; P. -A. Söderström; J. L. Tain; S. Tanguy; S. Tashenov; Ch. Theisen; J. Thornhill; F. Tomasi; N. Toniolo; R. Touzery; B. Travers; A. Triossi; M. Tripon; K. M. M. Tun-Lanoë; M. Turcato; C. Unsworth; C. A. Ur; J. J. Valiente-Dobon; V. Vandone; E. Vardaci; R. Venturelli; F. Veronese; Ch. Veyssiere; E. Viscione; R. Wadsworth; P. M. Walker; N. Warr; C. Weber; D. Weisshaar; D. Wells; O. Wieland; A. Wiens; G. Wittwer; H. J. Wollersheim; F. Zocca; N. V. Zamfir; M. Zi?bli?ski; A. Zucchiatti

    2012-09-17

    The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation gamma-ray spectrometer. AGATA is based on the technique of gamma-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a gamma ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realization of gamma-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly-segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterization of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximize its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer.

  5. 2012 Spring : Highly Distinguished Honors Highly Distinguished

    E-Print Network [OSTI]

    Kunkle, Tom

    Distinguished Bell Lauren Ashley Highly Distinguished Benjamin Abigail Highly Distinguished Benson Alexandrea Hannah Elizabeth Highly Distinguished Bishop Anna Laurel Highly Distinguished Black Caitlin Emily Highly

  6. 2014 Fall : Highly Distinguished Honors Highly Distinguished

    E-Print Network [OSTI]

    Kunkle, Tom

    Morgan Highly Distinguished Beech Kaylie Schaefer Highly Distinguished Bell Brandi Lakeisha Highly Distinguished Billard Caitlin Rose Highly Distinguished Birk Christian Gustave Highly Distinguished Birkhead

  7. Diamond detector for high rate monitors of fast neutrons beams

    SciTech Connect (OSTI)

    Giacomelli, L.; Rebai, M.; Cippo, E. Perelli; Tardocchi, M.; Fazzi, A.; Andreani, C.; Pietropaolo, A.; Frost, C. D.; Rhodes, N.; Schooneveld, E.; Gorini, G.

    2012-06-19

    A fast neutron detection system suitable for high rate measurements is presented. The detector is based on a commercial high purity single crystal diamond (SDD) coupled to a fast digital data acquisition system. The detector was tested at the ISIS pulsed spallation neutron source. The SDD event signal was digitized at 1 GHz to reconstruct the deposited energy (pulse amplitude) and neutron arrival time; the event time of flight (ToF) was obtained relative to the recorded proton beam signal t{sub 0}. Fast acquisition is needed since the peak count rate is very high ({approx}800 kHz) due to the pulsed structure of the neutron beam. Measurements at ISIS indicate that three characteristics regions exist in the biparametric spectrum: i) background gamma events of low pulse amplitudes; ii) low pulse amplitude neutron events in the energy range E{sub dep}= 1.5-7 MeV ascribed to neutron elastic scattering on {sup 12}C; iii) large pulse amplitude neutron events with E{sub n} < 7 MeV ascribed to {sup 12}C(n,{alpha}){sup 9}Be and 12C(n,n')3{alpha}.

  8. Hydrogen, lithium, and lithium hydride production

    DOE Patents [OSTI]

    Brown, Sam W; Spencer, Larry S; Phillips, Michael R; Powell, G. Louis; Campbell, Peggy J

    2014-03-25

    A method of producing high purity lithium metal is provided, where gaseous-phase lithium metal is extracted from lithium hydride and condensed to form solid high purity lithium metal. The high purity lithium metal may be hydrided to provide high purity lithium hydride.

  9. Lignol Innovations, Inc. Demonstration-Scale Biorefinery

    Broader source: Energy.gov [DOE]

    The Lignol Innovations, Inc., biorefinery will produce cellulosic ethanol, high purity lignin, and furfural from hardwoods.

  10. A Balloon-borne Measurement of High Latitude Atmospheric Neutrons Using a LiCAF Neutron Detector

    E-Print Network [OSTI]

    Kole, Merlin; Fukuda, Kentaro; Ishizu, Sumito; Jackson, Miranda; Kamae, Tune; Kawaguchi, Noriaki; Kawano, Takafumi; Kiss, Mózsi; Moretti, Elena; Salinas, Maria Fernanda Muñoz; Pearce, Mark; Rydström, Stefan; Takahashi, Hiromitsu; Yanagida, Takayuki

    2013-01-01

    PoGOLino is a scintillator-based neutron detector. Its main purpose is to provide data on the neutron flux in the upper stratosphere at high latitudes at thermal and nonthermal energies for the PoGOLite instrument. PoGOLite is a balloon borne hard X-ray polarimeter for which the main source of background stems from high energy neutrons. No measurements of the neutron environment for the planned flight latitude and altitude exist. Furthermore this neutron environment changes with altitude, latitude and solar activity, three variables that will vary throughout the PoGOLite flight. PoGOLino was developed to study the neutron environment and the influences from these three variables upon it. PoGOLino consists of two Europium doped Lithium Calcium Aluminium Fluoride (Eu:LiCAF) scintillators, each of which is sandwiched between 2 Bismuth Germanium Oxide (BGO) scintillating crystals, which serve to veto signals produced by gamma-rays and charged particles. This allows the neutron flux to be measured even in high rad...

  11. Percolating porosity in ultrafine grained copper processed by High Pressure Torsion

    SciTech Connect (OSTI)

    Wegner, Matthias Leuthold, Jörn; Peterlechner, Martin; Divinski, Sergiy V. Wilde, Gerhard; Setman, Daria; Zehetbauer, Michael; Pippan, Reinhard

    2013-11-14

    Defect structures in copper of different purity (nominally 99.99 and 99.999?wt.?%) deformed via High Pressure Torsion (HPT) with varying processing parameters are investigated utilizing the radiotracer diffusion technique. While the degree of deformation is kept constant, the effects of applied quasi-hydrostatic pressure, processing temperature, post-deformation annealing treatments, and of the impurity concentration on the deformed samples are analyzed in terms of the formation of interconnected internal porosity. Furthermore, the anisotropy of the developing porosity network is examined. The porosity channels occurred to be interconnected along the direction parallel to the surface normal with a volume fraction of the order of a few ppm while no long-range penetration along the internal porosity could be detected when measured along the azimuthal or radial directions of a HPT processed sample.

  12. Determination of uranium and thorium in semiconductor memory materials by high fluence neutron activation analysis

    SciTech Connect (OSTI)

    Dyer, F.F.; Emery, J.F.; Northcutt, K.J.; Scott, R.M.

    1981-01-01

    Uranium and thorium were measured by absolute neutron activation analysis in high-purity materials used to manufacture semiconductor memories. The main thrust of the study concerned aluminum and aluminum alloys used as sources for thin film preparation, evaporated metal films, and samples from the Czochralski silicon crystal process. Average levels of U and Th were found for the source alloys to be approx. 65 and approx. 45 ppB, respectively. Levels of U and Th in silicon samples fell in the range of a few parts per trillion. Evaporated metal films contained about 1 ppB U and Th, but there is some question about these results due to the possibility of contamination.

  13. Low background high efficiency radiocesium detection system based on positron emission tomography technology

    SciTech Connect (OSTI)

    Yamamoto, Seiichi; Ogata, Yoshimune [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673 (Japan)] [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673 (Japan)

    2013-09-15

    After the 2011 nuclear power plant accident at Fukushima, radiocesium contamination in food became a serious concern in Japan. However, low background and high efficiency radiocesium detectors are expensive and huge, including semiconductor germanium detectors. To solve this problem, we developed a radiocesium detector by employing positron emission tomography (PET) technology. Because {sup 134}Cs emits two gamma photons (795 and 605 keV) within 5 ps, they can selectively be measured with coincidence. Such major environmental gamma photons as {sup 40}K (1.46 MeV) are single photon emitters and a coincidence measurement reduces the detection limit of radiocesium detectors. We arranged eight sets of Bi{sub 4}Ge{sub 3}O{sub 12} (BGO) scintillation detectors in double rings (four for each ring) and measured the coincidence between these detectors using PET data acquisition system. A 50 × 50 × 30 mm BGO was optically coupled to a 2 in. square photomultiplier tube (PMT). By measuring the coincidence, we eliminated most single gamma photons from the energy distribution and only detected those from {sup 134}Cs at an average efficiency of 12%. The minimum detectable concentration of the system for the 100 s acquisition time is less than half of the food monitor requirements in Japan (25 Bq/kg). These results show that the developed radiocesium detector based on PET technology is promising to detect low level radiocesium.

  14. An actively vetoed Clover gamma-detector for nuclear astrophysics at LUNA

    E-Print Network [OSTI]

    LUNA collaboration; T. Szucs; D. Bemmerer; C. Broggini; A. Caciolli; F. Confortola; P. Corvisiero; Z. Elekes; A. Formicola; Zs. Fulop; G. Gervino; A. Guglielmetti; C. Gustavino; Gy. Gyurky; G. Imbriani; M. Junker; A. Lemut; M. Marta; C. Mazzocchi; R. Menegazzo; P. Prati; V. Roca; C. Rolfs; C. Rossi Alvarez; E. Somorjai; O. Straniero; F. Strieder; F. Terrasi; H. P. Trautvetter

    2010-03-31

    An escape-suppressed, composite high-purity germanium detector of the Clover type has been installed at the Laboratory for Underground Nuclear Astrophysics (LUNA) facility, deep underground in the Gran Sasso Laboratory, Italy. The laboratory gamma-ray background of the Clover detector has been studied underground at LUNA and, for comparison, also in an overground laboratory. Spectra have been recorded both for the single segments and for the virtual detector formed by online addition of all four segments. The effect of the escape-suppression shield has been studied as well. Despite their generally higher intrinsic background, escape-suppressed detectors are found to be well suited for underground nuclear astrophysics studies. As an example for the advantage of using a composite detector deep underground, the weak ground state branching of the Ep = 223 keV resonance in the 24Mg(p,gamma)25Al reaction is determined with improved precision.

  15. Reconstruction of a Radiation Point Source's Radial Location Using Goodness-of-Fit Test on Spectra Obtained from an HPGe Detector

    E-Print Network [OSTI]

    L. T. Evans; K. Andre; R. De; R. Henning; E. D. Morgan

    2009-08-16

    High purity germanium (HPGe) detectors are ubiquitous in nuclear physics experiments and are also used in numerous low radioactive background detectors. The effect of the position of $^{60}$Co and $^{137}$Cs point sources on the shape of spectra were studied with Monte Carlo and HPGe detector measurements. We briefly confirm previous work on the position dependence of relative heights of peaks. Spectra taken with the radiation sources placed at locations around the detector were then compared using the Kolmogorov-Smirnov (K-S) goodness-of-fit test. We demonstrate that with this method the Compton continuum spectral shape has good sensitivity to the radial location of a point-source, but poor angular resolution. We conclude with a study of the position reconstruction accuracy as a function of the number of counts from the source.

  16. Low Background Counting At SNOLAB

    SciTech Connect (OSTI)

    Lawson, Ian; Cleveland, Bruce [SNOLAB, 1039 Regional Rd 24, Lively, ON P3Y 1N2 (Canada)

    2011-04-27

    It is a continuous and ongoing effort to maintain radioactivity in materials and in the environment surrounding most underground experiments at very low levels. These low levels are required so that experiments can achieve the required detection sensitivities for the detection of low-energy neutrinos, searches for dark matter and neutrinoless double-beta decay. SNOLAB has several facilities which are used to determine these low background levels in the materials and the underground environment. This proceedings will describe the SNOLAB High Purity Germanium Detector which has been in continuous use for the past five years and give results of many of the items that have been counted over that period. Brief descriptions of SNOLAB's alpha-beta and electrostatic counters will be given, and the radon levels at SNOLAB will be discussed.

  17. Testing the Ge detectors for the MAJORANA DEMONSTRATOR

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, W.; Abgrall, N.; Aguayo, E.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; et al

    2015-03-24

    High purity germanium (HPGe) crystals will be used for the MAJORANA DEMONSTRATOR, where they serve as both the source and the detector for neutrinoless double beta decay. It is crucial for the experiment to understand the performance of the HPGe crystals. A variety of crystal properties are being investigated, including basic properties such as energy resolution, efficiency, uniformity, capacitance, leakage current and crystal axis orientation, as well as more sophisticated properties, e.g. pulse shapes and dead layer and transition layer distributions. In this talk, we will present our measurements that characterize the HPGe crystals. We will also discuss the ourmore »simulation package for the detector characterization setup, and show that additional information can be extracted from data-simulation comparisons.« less

  18. Ion Implantation in Ge: Structural and electrical investigation of the induced lattice damage & Study of the lattice location of implanted impurities

    E-Print Network [OSTI]

    Decoster, Stefan; Wahl, Ulrich

    The past two decades, germanium has drawn international attention as one of the most promising materials to replace silicon in semiconductor applications. Due to important advantages with respect to Si, such as the increased electron and hole mobility, Ge is well on its way to become an important material in future high-speed integrated circuits. Although the interest in this elemental group IV semiconductor is increasing rapidly nowadays, the number of publications about this material is still relatively scarce, especially when compared to Si. The most widely used technique to dope semiconductors is ion implantation, due to its good control of the dopant concentration and profile, and the isotopic purity of the implanted species. However, there is a major lack of knowledge of the fundamental properties of ion implantation in Ge, which has triggered the research presented in this thesis. One of the most important and generally unwanted properties of ion implantation is the creation of damage to the crystal la...

  19. Measurement of airborne fission products in Chapel Hill, NC, USA from the Fukushima Dai-ichi reactor accident

    E-Print Network [OSTI]

    S. MacMullin; G. K. Giovanetti; M. P. Green; R. Henning; R. Holmes; K. Vorren; J. F. Wilkerson

    2012-10-03

    We present measurements of airborne fission products in Chapel Hill, NC, USA, from 62 days following the March 11, 2011, accident at the Fukushima Dai-ichi nuclear power plant. Airborne particle samples were collected daily in air filters and radio-assayed with two high-purity germanium (HPGe) detectors. The fission products I-131 and Cs-137 were measured with maximum activities of 4.2 +/- 0.6 mBq/m^3 and 0.42 +/- 0.07 mBq/m^3 respectively. Additional activity from I-131, I-132, Cs-134, Cs-136, Cs-137 and Te-132 were measured in the same air filters using a low-background HPGe detector at the Kimballton Underground Research Facility (KURF).

  20. Revalidation of the isobaric multiplet mass equation for the $A=20$ quintet

    E-Print Network [OSTI]

    B. E. Glassman; D. Pérez-Loureiro; C. Wrede; J. Allen; D. W. Bardayan; M. B. Bennett; B. A. Brown; K. A. Chipps; M. Febbraro; C. Fry; M. R. Hall; O. Hall; S. N. Liddick; P. O'Malley; W. Ong; S. D. Pain; S. B. Schwartz; P. Shidling; H. Sims; P. Thompson; H. Zhang

    2015-11-05

    An unexpected breakdown of the isobaric multiplet mass equation in the $A=20$, $T=2$ quintet was recently reported, presenting a challenge to modern theories of nuclear structure. In the present work, the excitation energy of the lowest $T = 2$ state in $^{20}$Na has been measured to be $6498.4 \\pm 0.2_{\\textrm{stat}} \\pm 0.4_{\\textrm{syst}}$ keV by using the superallowed $0^+ \\rightarrow 0^+$ beta decay of $^{20}$Mg to access it and an array of high-purity germanium detectors to detect its $\\gamma$-ray deexcitation. This value differs by 27 keV (1.9 standard deviations) from the recommended value of $6525 \\pm 14$ keV and is a factor of 28 more precise. The isobaric multiplet mass equation is shown to be revalidated when the new value is adopted.

  1. Testing the Ge detectors for the MAJORANA DEMONSTRATOR

    SciTech Connect (OSTI)

    Xu, W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Abgrall, N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Aguayo, E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Avignone, F. T. [Univ. of South Carolina, Columbia, SC (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Barabash, A. S. [Institute for Theoretical and Experimental Physics, Moscow (Russia); Bertrand, F. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boswell, M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brudanin, V. [Joint Institute for Nuclear Research, Dubna (Russia); Busch, M. [Duke Univ., Durham, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Byram, D. [Univ. of South Dakota, Vermillion, SD (United States); Caldwell, A. S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Chan, Y. -D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Christofferson, C. D. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Combs, D. C. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Cuesta, C. [Univ. of Washington, Seattle, WA (United States); Detwiler, J. A. [Univ. of Washington, Seattle, WA (United States); Doe, P. J. [Univ. of Washington, Seattle, WA (United States); Efremenko, Yu. [Univ. of Tennessee, Knoxville, TN (United States); Egorov, V. [Joint Institute for Nuclear Research, Dubna (Russia); Ejiri, H. [Osaka Univ., Osaka (Japan); Elliott, S. R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fast, J. E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Finnerty, P. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Fraenkle, F. M. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giovanetti, G. K. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Goett, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gruszko, J. [Univ. of Washington, Seattle, WA (United States); Guiseppe, V. E. [Univ. of South Carolina, Columbia, SC (United States); Gusev, K. [Joint Institute for Nuclear Research, Dubna (Russia); Hallin, A. L. [Univ. of Alberta, Edmonton, AB (Canada); Hazama, R. [Osaka Univ., Osaka (Japan); Hegai, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); North Carolina State Univ., Raleigh, NC (United States); Henning, R. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Hoppe, E. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Howard, S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Howe, M. A. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Keeter, K. J. [Black Hills State Univ., Spearfish, SD (United States); Kidd, M. F. [Tennessee Tech Univ., Cookeville, TN (United States); Kochetov, O. [Joint Institute for Nuclear Research, Dubna (Russia); Konovalov, S. I. [Institute for Theoretical and Experimental Physics, Moscow (Russia); Kouzes, R. T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); LaFerriere, B. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leon, J. [Univ. of Washington, Seattle, WA (United States); Leviner, L. E. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Loach, J. C. [Univ. of Washington, Seattle, WA (United States); MacMullin, J. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States)

    2015-01-01

    High purity germanium (HPGe) crystals will be used for the MAJORANA DEMONSTRATOR, where they serve as both the source and the detector for neutrinoless double beta decay. It is crucial for the experiment to understand the performance of the HPGe crystals. A variety of crystal properties are being investigated, including basic properties such as energy resolution, efficiency, uniformity, capacitance, leakage current and crystal axis orientation, as well as more sophisticated properties, e.g. pulse shapes and dead layer and transition layer distributions. In this talk, we will present our measurements that characterize the HPGe crystals. We will also discuss the our simulation package for the detector characterization setup, and show that additional information can be extracted from data-simulation comparisons.

  2. Ion-induced gamma-ray detection of fast ions escaping from fusion plasmas

    SciTech Connect (OSTI)

    Nishiura, M., E-mail: nishiura@ppl.k.u-tokyo.ac.jp; Mushiake, T. [Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561 (Japan); Doi, K.; Wada, M. [Graduate School of Science and Engineering, Doshisha University, Kyotanabe 610-0321 (Japan); Taniike, A.; Matsuki, T. [Graduate School of Maritime Sciences, Kobe University, Kobe 658-0022 (Japan); Shimazoe, K. [Graduate School of Engineering, The University of Tokyo, Tokyo 113-8654 (Japan); Yoshino, M. [Furukawa Co. Ltd., Tsukuba, Ibaraki 305-0856 (Japan); Nagasaka, T.; Tanaka, T.; Kisaki, M. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Fujimoto, Y.; Fujioka, K. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan); Yamaoka, H. [RIKEN SPring-8 center, RIKEN, Sayo, Hyogo 679-5148 (Japan); Matsumoto, Y. [Tokushima Bunri University, Tokushima 770-8514 (Japan)

    2014-11-15

    A 12 × 12 pixel detector has been developed and used in a laboratory experiment for lost fast-ion diagnostics. With gamma rays in the MeV range originating from nuclear reactions {sup 9}Be(?, n?){sup 12}C, {sup 9}Be(d, n?){sup 12}C, and {sup 12}C(d, p?){sup 13}C, a high purity germanium (HPGe) detector measured a fine-energy-resolved spectrum of gamma rays. The HPGe detector enables the survey of background-gamma rays and Doppler-shifted photo peak shapes. In the experiments, the pixel detector produces a gamma-ray image reconstructed from the energy spectrum obtained from total photon counts of irradiation passing through the detector's lead collimator. From gamma-ray image, diagnostics are able to produce an analysis of the fast ion loss onto the first wall in principle.

  3. Construction and Testing of a Low-power Cryostat for MARS

    SciTech Connect (OSTI)

    Aalseth, Craig E.; Caggiano, Joseph A.; Day, Anthony R.; Fast, James E.; Fuller, Erin S.

    2007-10-01

    A low-power cryostat was designed and built for the Multi-sensor Airborne Radiation Survey (MARS) project for the purpose of housing a close-packed high-purity germanium (HPGe) detector array of 14 HPGe detectors. The power consumption of the cold mass in the cryostat was measured to be 4.07(11) watts, sufficient for 5.5 days of continuous operation using only 8 liters of liquid nitrogen. Temperatures throughout the cryostat were measured by platinum resistance temperature detectors. These measurements were used to determine the emissivity of the copper used in the floating radiation shield and outer cryostat wall, which was constructed using chemically cleaned and passivated copper metal. Using a PNNL-developed passivation process, an emissivity of 2.5(3)% was achieved for copper.

  4. In situ determination of /sup 241/Am on Enewetak Atoll. Date of survey: July 1977-December 1979

    SciTech Connect (OSTI)

    Tipton, W.J.; Fritzsche, A.E.; Jaffe, R.J.; Villaire, A.E.

    1981-11-01

    An in situ gamma ray spectrometer system was operated at Enewetak Atoll from July 1977 to December 1979 in support of the Enewetak Cleanup Project. The system employed a high purity germanium planar detector suspended at a height of 7.4 m above ground. Conversion factors were established to relate measured photopeak count rate data to source concentration in the soil. Data obtained for /sup 241/Am, together with plutonium-to-americium ratios obtained from soil sample analyses, were used to establish area-averaged surface (0 to 3 cm) transuranic concentration values. In areas which exceeded cleanup criteria, measurements were made in an iterative fashion to guide soil removal until levels were reduced below the cleanup criteria. Final measurements made after soil removal had been completed were used to document remaining surface transuranic concentration values and to establish external exposure rate levels due to /sup 137/Cs and /sup 60/Co.

  5. Measurement of the neutron-capture cross section of ??Ge and ??Ge below 15 MeV and its relevance to 0??? decay searches of ??Ge

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bhike, Megha; Fallin, B.; Tornow, W.

    2015-02-01

    The neutron radiative-capture cross section of ??Ge was measured between 0.4 and 14.8 MeV using the activation technique. Germanium samples with the isotopic abundance of ~86% ??Ge and ~14% ??Ge used in the 0??? searches by the GERDA and Majorana Collaborations were irradiated with monoenergetic neutrons produced at eleven energies via the ³H(p,n)³He, ²H(d,n)³He and ³H(d,n)?He reactions. Previously, data existed only at thermal energies and at 14 MeV. As a by-product, capture cross-section data were also obtained for ??Ge at neutron energies below 8 MeV. Indium and gold foils were irradiated simultaneously for neutron fluence determination. High-resolution ?-ray spectroscopy wasmore »used to determine the ?-ray activity of the daughter nuclei of interest. For the ??Ge total capture cross section the present data are in good agreement with the TENDL-2013 model calculations and the ENDF/B-VII.1 evaluations, while for the ??Ge(n,?)??Ge reaction, the present data are about a factor of two larger than predicted. It was found that the ??Ge(n,?)??Ge yield in the High-Purity Germanium (HPGe) detectors used by the GERDA and Majorana Collaborations is only about a factor of two smaller than the ??Ge(n,?)??Ge yield due to the larger cross section of the former reaction.« less

  6. CO2/oxalate Cathodes as Safe and Efficient Alternatives in High Energy Density Metal-Air Type Rechargeable Batteries

    E-Print Network [OSTI]

    Nemeth, Karoly

    2013-01-01

    We present theoretical analysis on why and how rechargeable metal-air type batteries can be made significantly safer and more practical by utilizing CO2/oxalate conversions instead of O2/peroxide or O2/hydroxide ones, in the positive electrode. Metal-air batteries, such as the Li-air one, may have very large energy densities, comparable to that of gasoline, theoretically allowing for long range all-electric vehicles. There are, however, still significant challenges, especially related to the safety of their underlying chemistries, the robustness of their recharging and the need of supplying high purity O2 from air to the battery. We point out that the CO2/oxalate reversible electrochemical conversion is a viable alternative of the O2-based ones, allowing for similarly high energy density and almost identical voltage, while being much safer through the elimination of aggressive oxidant peroxides and the use of thermally stable, non-oxidative and environmentally benign oxalates instead.

  7. High-Efficiency Amorphous Silicon Alloy Based Solar Cells and Modules; Final Technical Progress Report, 30 May 2002--31 May 2005

    SciTech Connect (OSTI)

    Guha, S.; Yang, J.

    2005-10-01

    The principal objective of this R&D program is to expand, enhance, and accelerate knowledge and capabilities for development of high-efficiency hydrogenated amorphous silicon (a-Si:H) and amorphous silicon-germanium alloy (a-SiGe:H) related thin-film multijunction solar cells and modules with low manufacturing cost and high reliability. Our strategy has been to use the spectrum-splitting triple-junction structure, a-Si:H/a-SiGe:H/a-SiGe:H, to improve solar cell and module efficiency, stability, and throughput of production. The methodology used to achieve the objectives included: (1) explore the highest stable efficiency using the triple-junction structure deposited using RF glow discharge at a low rate, (2) fabricate the devices at a high deposition rate for high throughput and low cost, and (3) develop an optimized recipe using the R&D batch large-area reactor to help the design and optimization of the roll-to-roll production machines. For short-term goals, we have worked on the improvement of a-Si:H and a-SiGe:H alloy solar cells. a-Si:H and a-SiGe:H are the foundation of current a-Si:H based thin-film photovoltaic technology. Any improvement in cell efficiency, throughput, and cost reduction will immediately improve operation efficiency of our manufacturing plant, allowing us to further expand our production capacity.

  8. High-Performance Sorbents for Carbon Dioxide Capture from Air

    SciTech Connect (OSTI)

    Sholl, David; Jones, Christopher

    2013-03-13

    This project has focused on capture of CO{sub 2} from ambient air (“air capture”). If this process is technically and economically feasible, it could potentially contribute to net reduction of CO{sub 2} emissions in ways that are complementary to better developed techniques for CO{sub 2} from concentrated point sources. We focused on cyclic adsorption processes for CO{sub 2} capture from air in which the entire cycle is performed at moderate temperatures. The project involved both experimental studies of sorbent materials and process level modeling of cyclic air capture processes. In our experimental work, a series of amine-functionalized silica adsorbents were prepared and characterized to determine the impact of molecular architecture on CO{sub 2} capture. Some key findings were: • Amine functionalized silicas can be prepared with high enough CO{sub 2} capacities under ambient conditions to merit consideration for use in air capture processes. • Primary amines are better candidates for CO{sub 2} capture than secondary or tertiary amines, both in terms of amine efficiency for CO{sub 2} adsorption and enhanced water affinity. • Mechanistic understanding of degradation of these materials can enable control of molecular architecture to significantly improve material stability. Our process modeling work provided the first publically available cost and energy estimates for cyclic adsorption processes for air capture of CO{sub 2}. Some key findings were: • Cycles based on diurnal ambient heating and cooling cannot yield useful purities or amounts of captured CO{sub 2}. • Cycles based on steam desorption at 110 oC can yield CO{sub 2} purities of ~88%. • The energy requirements for cycles using steam desorption are dominated by needs for thermal input, which results in lower costs than energy input in the form of electricity. Cyclic processes with operational costs of less than $100 tCO{sub 2}-net were described, and these results point to process and material improvements that could substantially reduce these costs. The most critical conclusions from our work are that (i) CO{sub 2} capture from ambient air using moderate temperature cyclic adsorption processes is technically feasible and (ii) the operational costs of realistic versions of these processes are moderate enough to encourage future development of this technology. Because of the very modest net investment that has been made in R&D associated with this approach from all sources worldwide (relative to the massive public and private investment that has been made in technologies for CO{sub 2} from concentrated point sources), our results strongly suggest that continued development of air capture is justified.

  9. Photoelectron yield in the prototype of the liquid argon detector for CDEX-10

    E-Print Network [OSTI]

    Qing-Hao Chen; Qian Yue; Jian-Ping Cheng; Ke-Jun Kang; Yuan-Jing Li; Shin-Ted Lin; Chang-Jian Tang; Hao-Yang Xing; Xun-Zhen Yu; Ming Zeng

    2015-12-14

    The China Dark Matter Experiment (CDEX) is a low background experiment at China Jinping Underground Laboratory (CJPL) designed to directly detect dark matter with a high-purity germanium (HPGe) detector. In the second phase CDEX-10 with 10 kg germanium array detector system, the liquid argon (LAr) anti-Compton active shielding and cooling system is proposed. For purpose of studying the properties of LAr detector, a prototype with an active volume of 7 liters of liquid argon was built and operated. The photoelectron yields, as a critically important parameter for the LAr detector, have been measured to be 0.051-0.079 p.e./keV for 662 keV gamma lines at different positions. The good agreement between the experimental and simulation results has provided a quite reasonable understanding and determination of the important parameters such as the Surviving Fraction of the $Ar_{2}^{*}$ excimers, the absorption length for 128 nm photons in liquid argon, the reflectivity of Teflon and so on.

  10. NID Copper Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Zhu, Zihua

    2011-02-01

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). This experiment requires the use of germanium isotopically enriched in 76Ge. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  11. Operation of a GERDA Phase I prototype detector in liquid argon and nitrogen

    E-Print Network [OSTI]

    M. Barnabé Heider; A. Bakalyarov; L. Bezrukov; C. Cattadori; O. Chkvorets; K. Gusev; M. Hult; I. Kirpichnikov; V. Lebedev; G. Marissens; P. Peiffer; S. Schönert; M. Shirchenko; A. Smolnikov; A. Vasenko; S. Vasiliev; S. Zhukov

    2008-12-20

    The GERDA (GERmanium Detector Array) experiment aiming to search for the neutrinoless double beta decay of 76Ge at the Laboratori Nazionali Del Gran Sasso (LNGS), Italy, will operate bare enriched high-purity germanium (HPGe) detectors in liquid argon. GERDA Phase I will use the enriched diodes from the previous Heidelberg-Moscow (HdM) and IGEX experiments. With the HPGe detectors mounted in a low-mass holder, GERDA aims at an excellent energy resolution and extremely low background. The goal is to check the claim for the neutrinoless double beta decay evidence in the HdM 76Ge experiment within one year of data taking. Before dismounting the enriched diodes from their cryostat, the performance parameters of the HdM and the IGEX detectors have been measured. The diodes have been removed from their cryostats, their dimensions measured and they have been put under va-cuum in a transportation container. They are now being refurbished for GERDA Phase I at Canberra Semiconductor NV. Before operating the enriched diodes, a non-enriched HPGe p-type detector mounted in a low-mass holder is operated in the liquid argon test facility of the GERDA Detector Laboratory (GDL) at LNGS. Since January 2006, the testing of the prototype detector is being carried out in the GDL as well as at the site of the detector manufacturer.

  12. Majorana Demonstrator Bolted Joint Mechanical and Thermal Analysis

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Reid, Douglas J.; Fast, James E.

    2012-06-01

    The MAJORANA DEMONSTRATOR is designed to probe for neutrinoless double-beta decay, an extremely rare process with a half-life in the order of 1026 years. The experiment uses an ultra-low background, high-purity germanium detector array. The germanium crystals are both the source and the detector in this experiment. Operating these crystals as ionizing radiation detectors requires having them under cryogenic conditions (below 90 K). A liquid nitrogen thermosyphon is used to extract the heat from the detectors. The detector channels are arranged in strings and thermally coupled to the thermosyphon through a cold plate. The cold plate is joined to the thermosyphon by a bolted joint. This circular plate is housed inside the cryostat can. This document provides a detailed study of the bolted joint that connects the cold plate and the thermosyphon. An analysis of the mechanical and thermal properties of this bolted joint is presented. The force applied to the joint is derived from the torque applied to each one of the six bolts that form the joint. The thermal conductivity of the joint is measured as a function of applied force. The required heat conductivity for a successful experiment is the combination of the thermal conductivity of the detector string and this joint. The thermal behavior of the joint is experimentally implemented and analyzed in this study.

  13. Particle Release Experiment (PRex) Final Report

    SciTech Connect (OSTI)

    Keillor, Martin E.; Arrigo, Leah M.; Detwiler, Rebecca S.; Kernan, Warnick J.; Kirkham, Randy R.; MacDougall, Matthew R.; Chipman, Veraun D.; Milbrath, Brian D.; Rishel, Jeremy P.; Seifert, Allen; Seifert, Carolyn E.; Smart, John E.; Emer, Dudley

    2014-09-30

    An experiment to release radioactive particles representative of small-scale venting from an underground nuclear test was conducted to gather data in support of treaty verification and monitoring activities. For this experiment, a CO2-driven “air cannon” was used to release La-140 at ambient temperatures. Lanthanum-140 was chosen to represent the fission fragments because of its short half-life and prominent gamma-ray emissions; the choice was also influenced by the successful production and use of La-140 with low levels of radioactive contaminants in a Defence Research and Development Canada Field Trial. The source was created through activation of high-purity natural lanthanum oxide at the reactor of Washington State University, Pullman, Washington. Multiple varieties of witness plates and air samplers were laid in an irregular grid covering the area over which the plume was modeled to deposit. Aerial survey, a NaI(Tl) mobile spectrometer, and handheld and backpack instruments ranging from polyvinyl toluene to high-purity germanium were used to survey the plume. Additionally, three varieties of soil sampling were investigated. The relative sensitivity and utility of sampling and survey methods are discussed in the context of On-Site Inspection. The measurements and samples show a high degree of correlation and form a valuable set of test data.

  14. Optimization of Oxygen Purity for Coal Conversion Energy Reduction 

    E-Print Network [OSTI]

    Baker, C. R.; Pike, R. A.

    1982-01-01

    or liquefaction. Gasification of coal is a partial oxidation process in which steam and oxygen are reacted with coal to produce a mixture of hydrogen and carbon monoxide plus a number of other components. This mixture has a heating value of about 300 Btu..., or hydrocarbon liquids. The synthesis gas mixture can also be converted by means of the water gas shift reaction to produce hydrogen Which, in turn, can be reacted with coal to form hydrocarbon liquids by direct liquefaction techniques. Oxygen is required...

  15. Inventing purity in the Atlantic sugar world, 1860-1930

    E-Print Network [OSTI]

    Singerman, David Roth

    2014-01-01

    This dissertation illuminates how expert labor makes a complex natural substance into a uniform global commodity. Drawing on both published sources and extensive archival research in the continental United States, in ...

  16. Carbohydrate markers of organism purity and growth environment

    SciTech Connect (OSTI)

    Wunschel, David S.; Fox, Alvin

    2012-01-01

    Recent experience with Bacillus spore characterization has demonstrated that carbohydrate content can provide potentially vital bioforensic information. Like other metabolites, the carbohydrate profiles of samples reflect variations in cellular structures as well as presence of residual carbohydrates from the medium found as trace components. The presence and characteristics of residual carbohydrates, such as agar, represent strong indicators of culturing method. The methods to detect residual carbohydrates can be extended to other compounds used in processing and preservation of microbes in a dry form.

  17. U.S. Department of Energy National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Impact FR Federal Register Ge-68 germanium-68 GHG greenhouse gas HEPA high-efficiency particulate air HMP Habitat Management Plan HVAC heating, ventilation, and cooling...

  18. Electrical behavior of atomic layer deposited high quality SiO{sub 2} gate dielectric

    SciTech Connect (OSTI)

    Pradhan, Sangram K.; Tanyi, Ekembu K.; Skuza, Jonathan R.; Xiao, Bo; Pradhan, Aswini K., E-mail: apradhan@nsu.edu [Center for Materials Research, Norfolk State University, 700 Park Ave., Norfolk, Virginia 23504 (United States)

    2015-01-01

    Comprehensive and systematic electrical studies were performed on fabrication of high quality SiO{sub 2} thin films MOS capacitor using the robust, novel, and simple atomic layer deposition (ALD) technique using highly reactive ozone and tris (dimethylamino) silane (TDMAS) precursors. Ideal capacitance–voltage curve exhibits a very small frequency dispersion and hysteresis behavior of the SiO{sub 2} MOS capacitor grown at 1?s TDMAS pulse, suggesting excellent interfacial quality and purity of the film as probed using x-ray photoelectron studies. The flat-band voltage of the device shifted from negative toward positive voltage axis with increase of TDMAS pulses from 0.2 to 2 s. Based on an equivalent oxide thickness point of view, all SiO{sub 2} films have gate leakage current density of (5.18?×?10{sup ?8} A/cm{sup 2}) as well as high dielectric break down fields of more than (?10 MV/cm), which is better and comparable to that of thermally grown SiO{sub 2} at temperatures above 800?°C. These appealing electrical properties of ALD grown SiO{sub 2} thin films enable its potential applications such as high-quality gate insulators for thin film MOS transistors, as well as insulators for sensor and nanostructures on nonsilicon substrates.

  19. Fabrication of Tungsten-Rhenium Cladding materials via Spark Plasma Sintering for Ultra High Temperature Reactor Applications

    SciTech Connect (OSTI)

    Charit, Indrajit; Butt, Darryl; Frary, Megan; Carroll, Mark

    2012-11-05

    This research will develop an optimized, cost-effective method for producing high-purity tungsten-rhenium alloyed fuel clad forms that are crucial for the development of a very high-temperature nuclear reactor. The study will provide critical insight into the fundamental behavior (processing-microstructure- property correlations) of W-Re alloys made using this new fabrication process comprising high-energy ball milling (HEBM) and spark plasma sintering (SPS). A broader goal is to re-establish the U.S. lead in the research field of refractory alloys, such as W-Re systems, with potential applications in very high-temperature nuclear reactors. An essential long-term goal for nuclear power is to develop the capability of operating nuclear reactors at temperatures in excess of 1,000K. This capability has applications in space exploration and some special terrestrial uses where high temperatures are needed in certain chemical or reforming processes. Refractory alloys have been identified as being capable of withstanding temperatures in excess of 1,000K and are considered critical for the development of ultra hightemperature reactors. Tungsten alloys are known to possess extraordinary properties, such as excellent high-temperature capability, including the ability to resist leakage of fissile materials when used as a fuel clad. However, there are difficulties with the development of refractory alloys: 1) lack of basic experimental data on thermodynamics and mechanical and physical properties, and 2) challenges associated with processing these alloys.

  20. Road Map for Studies to Produce Consistent and High Performance SRF Accelerator Structures

    SciTech Connect (OSTI)

    Ganapati Rao Myneni; John F. O’Hanlon

    2007-06-20

    Superconducting Radio Frequency (SRF) accelerator structures made from high purity niobium are becoming the technological choice for a large number of future accelerators and energy recovery LINAC’s (ERL). Most of the presently planned accelerators and ERL requirements will be met with some effort by the current SRF technology where accelerating gradients of about 20 MV/m can be produced on a routine basis with an acceptable yield. However, the XFEL at DESY and the planned ILC require acceleration gradients more than 28 MV/m and 35 MV/m respectively. At the recent ILC meeting at Snowmass (2005) concern was expressed regarding the wide spread in the achieved accelerator gradients and the relatively low yields. For obtaining accelerating gradients of 35 MV/m in SRF accelerator structures consistently, a deeper understanding of the causes for the spread has to be gained and advances have to be made in many scientific and high technology fields, including materials, surface and vacuum sciences, application of reliable processes and procedures, which provide contamination –free surfaces and avoid recontamination and cryogenics related technologies. In this contribution a road map for studies needed to produce consistent and high performance SRF accelerator structures from the needed materials development to clean and non-recontaminating processes and procedures will be presented.

  1. High Temperatures & Electricity Demand

    E-Print Network [OSTI]

    High Temperatures & Electricity Demand An Assessment of Supply Adequacy in California Trends.......................................................................................................1 HIGH TEMPERATURES AND ELECTRICITY DEMAND.....................................................................................................................7 SECTION I: HIGH TEMPERATURES AND ELECTRICITY DEMAND ..........................9 BACKGROUND

  2. Nanoporous, Metal Carbide, Surface Diffusion Membranes for High Temperature Hydrogen Separations

    SciTech Connect (OSTI)

    Way, J.; Wolden, Colin

    2013-09-30

    Colorado School of Mines (CSM) developed high temperature, hydrogen permeable membranes that contain no platinum group metals with the goal of separating hydrogen from gas mixtures representative of gasification of carbon feedstocks such as coal or biomass in order to meet DOE NETL 2015 hydrogen membrane performance targets. We employed a dual synthesis strategy centered on transition metal carbides. In the first approach, novel, high temperature, surface diffusion membranes based on nanoporous Mo{sub 2}C were fabricated on ceramic supports. These were produced in a two step process that consisted of molybdenum oxide deposition followed by thermal carburization. Our best Mo{sub 2}C surface diffusion membrane achieved a pure hydrogen flux of 367 SCFH/ft{sup 2} at a feed pressure of only 20 psig. The highest H{sub 2}/N{sub 2} selectivity obtained with this approach was 4.9. A transport model using “dusty gas” theory was derived to describe the hydrogen transport in the Mo{sub 2}C coated, surface diffusion membranes. The second class of membranes developed were dense metal foils of BCC metals such as vanadium coated with thin (< 60 nm) Mo{sub 2}C catalyst layers. We have fabricated a Mo{sub 2}C/V composite membrane that in pure gas testing delivered a H{sub 2} flux of 238 SCFH/ft{sup 2} at 600 °C and 100 psig, with no detectable He permeance. This exceeds the 2010 DOE Target flux. This flux is 2.8 times that of pure Pd at the same membrane thickness and test conditions and over 79% of the 2015 flux target. In mixed gas testing we achieved a permeate purity of ?99.99%, satisfying the permeate purity milestone, but the hydrogen permeance was low, ~0.2 SCFH/ft{sup 2}.psi. However, during testing of a Mo{sub 2}C coated Pd alloy membrane with DOE 1 feed gas mixture a hydrogen permeance of >2 SCFH/ft{sup 2}.psi was obtained which was stable during the entire test, meeting the permeance associated with the 2010 DOE target flux. Lastly, the Mo{sub 2}C/V composite membranes were shown to be stable for at least 168 hours = one week, including cycling at high temperature and alternating He/H{sub 2} exposure.

  3. Physical and Mechanical Properties of Niobium for SRF Science and Technology

    SciTech Connect (OSTI)

    Myneni, Ganapati Rao [Accelerator Division, Jefferson Lab, Newport News, Virginia (United States)

    2007-08-09

    Optimized mechanical and physical properties of high purity niobium are crucial for obtaining high performance SRF particle beam accelerator structures consistently. This paper summarizes these important material properties for both high purity polycrystalline and single crystal niobium.

  4. Physical and Mechanical Properties of Niobium for SRF Science and Technology

    SciTech Connect (OSTI)

    Ganapati Rao Myneni

    2006-10-31

    Optimized mechanical and physical properties of high purity niobium are crucial for obtaining high performance SRF particle beam accelerator structures consistently. This paper summarizes these important material properties for both high purity polycrystalline and single crystal niobium.

  5. High-Temperature-High-Volume Lifting for Enhanced Geothermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems High-Temperature-High-Volume Lifting for...

  6. High Efficiency, Illumination Quality OLEDs for Lighting

    SciTech Connect (OSTI)

    Joseph Shiang; James Cella; Kelly Chichak; Anil Duggal; Kevin Janora; Chris Heller; Gautam Parthasarathy; Jeffery Youmans; Joseph Shiang

    2008-03-31

    The goal of the program was to demonstrate a 45 lumen per watt white light device based upon the use of multiple emission colors through the use of solution processing. This performance level is a dramatic extension of the team's previous 15 LPW large area illumination device. The fundamental material system was based upon commercial polymer materials. The team was largely able to achieve these goals, and was able to deliver to DOE a 90 lumen illumination source that had an average performance of 34 LPW a 1000 cd/m{sup 2} with peak performances near 40LPW. The average color temperature is 3200K and the calculated CRI 85. The device operated at a brightness of approximately 1000cd/m{sup 2}. The use of multiple emission colors particularly red and blue, provided additional degrees of design flexibility in achieving white light, but also required the use of a multilayered structure to separate the different recombination zones and prevent interconversion of blue emission to red emission. The use of commercial materials had the advantage that improvements by the chemical manufacturers in charge transport efficiency, operating life and material purity could be rapidly incorporated without the expenditure of additional effort. The program was designed to take maximum advantage of the known characteristics of these material and proceeded in seven steps. (1) Identify the most promising materials, (2) assemble them into multi-layer structures to control excitation and transport within the OLED, (3) identify materials development needs that would optimize performance within multilayer structures, (4) build a prototype that demonstrates the potential entitlement of the novel multilayer OLED architecture (5) integrate all of the developments to find the single best materials set to implement the novel multilayer architecture, (6) further optimize the best materials set, (7) make a large area high illumination quality white OLED. A photo of the final deliverable is shown. In 2003, a large area, OLED based illumination source was demonstrated that could provide light with a quality, quantity, and efficiency on par with what can be achieved with traditional light sources. The demonstration source was made by tiling together 16 separate 6-inch x 6-inch blue-emitting OLEDs. The efficiency, total lumen output, and lifetime of the OLED based illumination source were the same as what would be achieved with an 80 watt incandescent bulb. The devices had an average efficacy of 15 LPW and used solution-processed OLEDs. The individual 6-inch x 6-inch devices incorporated three technology strategies developed specifically for OLED lighting -- downconversion for white light generation, scattering for outcoupling efficiency enhancement, and a scalable monolithic series architecture to enable large area devices. The downconversion approach consists of optically coupling a blue-emitting OLED to a set of luminescent layers. The layers are chosen to absorb the blue OLED emission and then luminescence with high efficiency at longer wavelengths. The composition and number of layers are chosen so that the unabsorbed blue emission and the longer wavelength re-emission combine to make white light. A downconversion approach has the advantage of allowing a wide variety of colors to be made from a limited set of blue emitters. In addition, one does not have to carefully tune the emission wavelength of the individual electro-luminescent species within the OLED device in order to achieve white light. The downconversion architecture used to develop the 15LPW large area light source consisted of a polymer-based blue-emitting OLED and three downconversion layers. Two of the layers utilized perylene based dyes from BASF AG of Germany with high quantum efficiency (>98%) and one of the layers consisted of inorganic phosphor particles (Y(Gd)AG:Ce) with a quantum efficiency of {approx}85%. By independently varying the optical density of the downconversion layers, the overall emission spectrum could be adjusted to maximize performance for lighting (e.g. blackbody temp

  7. HIGH RESOLUTION AND FAST SCANNING SQUID BASED NON-DESTRUCTIVE INSPECTION SYSTEM OF NIOBIUM SHEETS FOR SRF CAVITIES

    SciTech Connect (OSTI)

    SHU, QUAN-SHENG

    2008-06-08

    Applications in high energy physics accelerators and other fields require the use of thousands of superconducting RF (SRF) cavities that are made of high purity Nb material and the purity of niobium is critical for these cavities to reach the highest accelerating fields. Tantalum is the most prolific of metal inclusions, which can cause thermal breakdown and prevent the cavities from reaching their theoretical performance limits of 45-50 MV/m, and DOE Labs are searching for a technology that could detect small impurities in superconducting Nb sheets reaching the highest possible accelerating fields. The proposed innovative SQUID-based Nondestructive system can scan Niobium sheets used in the manufacturing of SRF cavities with both high speed and high resolution. A highly sensitive SQUID system with a gradiometer probe, non-magnetic dewar, data acquisition system, and a scanning system will be developed for fast detection of impurities in planar Nb sheets. In phase I, we will modify our existing SQUID-based eddy current system to detect 100 micron size Ta defects and a great effort will focus on achieving fast scanning of a large number of niobium sheets in a shorter time and with reasonable resolution. An older system operated by moving the sample 1 mm, stopping and waiting for 1-2 seconds, then activating a measurement by the SQUID after the short settle time is modified. A preliminary designed and implemented a SQUID scanning system that is fast and is capable of scanning a 30 cm x 30 cm Nb sheet in 15 minutes by continuously moving the table at speeds up to 10 mm/s while activating the SQUID at 1mm interval is modified and reached the Phase I goal of 100mm resolution. We have successfully demonstrated the feasibility that a fast speed SQUID scanner without sacrificing the resolution of detection can be done, and a data acquisition and analysis system is also preliminary developed. The SQUID based scanner will help reach the highest accelerating field in SRF cavities that will provide a considerable cost reduction for new accelerators and for upgrades of existing accelerators. This will be realized either by reducing the length required for the SRF cavities or by the installation of higher gradient cavities for energy upgrades in the same space. The SQUID based scanner will also be used for the detection of defects on the surface, inside the bulk or at the back side of metallic sheets in other industries.

  8. High efficiency and high concentration in photovoltaics

    SciTech Connect (OSTI)

    Yamaguchi, Masafumi; Luque, A.

    1999-10-01

    In this paper, the authors present the state-of-the-art of multijunction solar cells and the future prospects of this technology. Their use in terrestrial applications will likely be for concentrators operating at very high concentrations. Some trends are also discussed and the authors present a cost calculation showing that highly efficient cells under very high concentration would be able to produce electricity at costs competitive with electricity generation costs for some utilities.

  9. Direct-Write of Silicon and Germanium Nanostructures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferencesPlatinum Fuel Cell Cathode

  10. Direct-Write of Silicon and Germanium Nanostructures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferencesPlatinum Fuel Cell CathodeDirect-Write of

  11. Direct-Write of Silicon and Germanium Nanostructures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferencesPlatinum Fuel Cell CathodeDirect-Write

  12. Direct-Write of Silicon and Germanium Nanostructures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferencesPlatinum Fuel Cell

  13. Medium energy ion implantation of Germanium into heated Silicon 

    E-Print Network [OSTI]

    McCoy, John Curtis

    1993-01-01

    Medium energy ion implantation of Ge into heated Si was investigated. legh fluence implants of Ge were made at energies of 40 or 60 keV into Si substrates at room temperature or heated to 300'C or higher. ...

  14. Study of Radioactive Impurities in Neutron Transmutation Doped Germanium

    E-Print Network [OSTI]

    S. Mathimalar; N. Dokania; V. Singh; V. Nanal; R. G. Pillay; A. Shrivastava; K. C. Jagadeesan; S. V. Thakare

    2014-11-27

    A program to develop low temperature (mK) sensors with neutron transmutation doped Ge for rare event studies with a cryogenic bolometer has been initiated. For this purpose, semiconductor grade Ge wafers are irradiated with thermal neutron flux from Dhruva reactor at BARC, Mumbai. Spectroscopic studies of irradiated samples have revealed that the environment of the capsule used for irradiating the sample leads to significant levels of $^{65}$Zn, $^{110}$Ag and $^{182}$Ta impurities, which can be reduced by chemical etching of approximately $\\sim50 \\mu$m thick surface layer. From measurements of the etched samples in the low background counting setup, activity due to trace impurities of $^{123}$Sb in bulk Ge is estimated to be $\\sim$ 1 Bq/gm after irradiation. These estimates indicate that in order to use the NTD Ge sensors for rare event studies, a cool down period of $\\sim$ 2 years would be necessary to reduce the radioactive background to $\\le$ 1 mBq/gm.

  15. Spin Transport and Relaxation in Graphene and Germanium

    E-Print Network [OSTI]

    Han, Wei

    2011-01-01

    steps: 3.1.1 Preparation of the graphene The graphene areKawakami, in preparation. 9.1 Introduction Graphene is

  16. Spin Transport and Relaxation in Graphene and Germanium

    E-Print Network [OSTI]

    Han, Wei

    2011-01-01

    1 1.1 Spintronics . . . . . . . .spintronics . . . . . . . . . . . . . . . . . . . . . . . . . .work on graphene spintronics . . . . . . . . . . .

  17. Spin Transport and Relaxation in Graphene and Germanium

    E-Print Network [OSTI]

    Han, Wei

    2011-01-01

    of choice for large scale spintronic applications [104], andtunnel barriers for spintronic devices, which are expectedfavorable for electronic and spintronic properties. Fig. 10-

  18. Spin Transport and Relaxation in Graphene and Germanium

    E-Print Network [OSTI]

    Han, Wei

    2011-01-01

    about the MBE chamber, cleanroom techniques, and magetism.liothography in the cleanroom. iv  I am also very greatfuljoking” with them in the cleanroom. Prof. Wang group (Yi

  19. Adsorption of Carbon, Silicon, and Germanium Adatoms on Graphene Sheet

    E-Print Network [OSTI]

    Cahyadi, Erica

    2012-01-01

    tunable bandgap in bilayer graphene. Nature 459: 820-23 (Can silicon behave like graphene? A first-principles study.IVA group atoms adsorption on graphene. J. Appl. Phys. 107,

  20. Improving the Cycling Life of Aluminum and Germanium Thin Films...

    Office of Scientific and Technical Information (OSTI)

    (SNL-NM), Albuquerque, NM (United States) Sponsoring Org: USDOE National Nuclear Security Administration (NNSA) Country of Publication: United States Language: English...

  1. Study of phonon modes in germanium nanowires and Ali Shakourib

    E-Print Network [OSTI]

    of Engineering, University of California, Santa Cruz, California 95064 Bin Yu, Xuhui Sun, and Meyya Meyyappan the size distribution of nanowires. © 2007 American Institute of Physics. DOI: 10 temperature was kept at room temperature 22 °C . Experiment was conducted in a clean room to minimize

  2. Structural origins of light emission in Germanium quantum

    E-Print Network [OSTI]

    Agnor, Craig B.

    (Image size) Data test (Time) QPALM ImageJ plugin 40nm 64*64*500 1 minute SOFI Matlab 20nm 64*64*500 1.5 minutes Rain- STORM Matlab Pixel size 64*64*500 1.5 minutes Direct-STORM C 20nm 64*64*500 7 minutes Decon-STORM Matlab Matlab 3 hours #12;Cell imaging

  3. Strained germanium thin film membrane on silicon substrate for optoelectronics

    E-Print Network [OSTI]

    Miller, David A. B.

    -temperature direct bandgap electroluminesence from Ge- on-Si light-emitting diodes," Opt. Lett. 34(8), 1198 temperature 1.6 microm electroluminescence from Ge light emitting diode on Si substrate," Opt. Express 17

  4. An analysis of a germanium diode detector circuit 

    E-Print Network [OSTI]

    Jones, Ray LaVon

    1956-01-01

    LIBRARY 4 g M C~LLEGE OF TEXAS AN ANALYSIS OF A GERMANIUIE DIODE DETECTOR CIRCUIT A Thesis Ray LaVon Jones Submitted. to the Graduate School of the Agricultural and IiIechanical Coils~. e of Texas in partial fulfillment of' the requirement... for the de, ;, :. roe of LIASTER OF SCIENICE August 1956 Major Subject: Electrical Engineering LIBRARY l k M COLLEGE OF TEXIIS AN ANALYSIS OE A G ", :A iIU: DIODE DJ''T ETON CINCUIT A Thesis i?ay LaVon Jones ApDroved. a; :o style and content by: a...

  5. Germanium: From Its Discovery to SiGe Devices

    E-Print Network [OSTI]

    Haller, E.E.

    2006-01-01

    technique to form p-n junctions beneath a silicion dioxideinvention of the junction transistor, both p-n-p and n-p-n,

  6. ELECTRICAL PROPERTIES OF DISLOCATIONS IN ULTRA-PURE GERMANIUM

    E-Print Network [OSTI]

    Hubbard, G. Scott

    2010-01-01

    Material-. , Volume 9. ELECTRICAL PROPERTIES OF DISLOCATIONS9. LBL-9342 MASTER ELECTRICAL PROPERTIES OF DISLOCATIONS IN9 4 7 M L3L-934? ELECTRICAL PROPERTIES Or DISLOCATIONS* IN

  7. Spin Transport and Relaxation in Graphene and Germanium

    E-Print Network [OSTI]

    Han, Wei

    2011-01-01

    metals, semiconductors, organics to graphene . . . . . . . .from metals, semiconductors, organics to graphene Fig. 1-4,semiconductor, and carbon-based materials are reviewed. A brief introduction to graphene

  8. Maximum likelihood analysis of low energy CDMS II germanium data

    E-Print Network [OSTI]

    Agnese, R.

    We report on the results of a search for a Weakly Interacting Massive Particle (WIMP) signal in low-energy data of the Cryogenic Dark Matter Search experiment using a maximum likelihood analysis. A background model is ...

  9. One-dimensional hole gas in germanium silicon nanowire heterostructures

    E-Print Network [OSTI]

    Cafarella, Michael J.

    , although the ability to vary size, material composition, and electronic properties of semiconductor nanow these materials, thus making them model platforms to study and use potentially unique properties of 1D systems (6 and semiconductor nanowires have at- tracted considerable attention as 1D structures for funda- mental studies

  10. Direct-Write of Silicon and Germanium Nanostructures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    using photoemission electron microscopes at ALS Beamlines 7.3.1 and 11.0.1. From Sand to Processor Modern electronic integrated circuits are made of silicon. Silicon is the...

  11. Thermal Transport Measurement of Silicon-Germanium Nanowires 

    E-Print Network [OSTI]

    Gwak, Yunki

    2010-10-12

    Thermal properties of one dimensional nanostructures are of interest for thermoelectric energy conversion. Thermoelectric efficiency is related to non dimensional thermoelectric figure of merit, ZT=S^2 o T/k, where S ,o , k and T are Seebeck...

  12. Low-energy tetrahedral polymorphs of carbon, silicon, and germanium

    E-Print Network [OSTI]

    Mujica, Andres; Pickard, Chris J.; Needs, Richard J.

    2015-06-08

    Searches for low-energy tetrahedral polymorphs of carbon and silicon have been performed using density functional theory computations and the ab initio random structure searching approach. Several of the hypothetical phases obtained in our searches...

  13. Thermoelectric Properties of Rare-Earth-Ruthenium-Germanium Compounds |

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired Solar FuelTechnologyTel: Name:Departmentand inreceiver survey

  14. Direct-Write of Silicon and Germanium Nanostructures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileep SinghLeadershipDirect

  15. Direct band gap electroluminescence from bulk germanium at room temperature

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing BacteriaConnectlaser-solidSwitchgrass|FeTe0.55Se0.45 (Journal Article)using an

  16. Erratum: ''Titanium and germanium lined hohlraums and halfraums as

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) | SciTech(Journal(Patent) |(JournalArticle)(Technicalthermalmulti-keV

  17. The Majorana Demonstrator: First Module of Germanium Detectors Comes Online

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S.Week Day Year(activeInforum LIFTMEMS Technology| U.S. DOE

  18. Electromechanically-cooled germanium radiation detector system (Conference)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansas Nuclear ProfileMultiferroicAward | Department ofElectromagnetic|

  19. High Performance Computing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    HPC INL Logo Home High-Performance Computing INL's high-performance computing center provides general use scientific computing capabilities to support the lab's efforts in advanced...

  20. High Performance Computing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Computing HPC High Performance Computing (HPC) Providing world-class high performance computing capability that enables unsurpassed solutions to complex problems of strategic...

  1. Towards the development of high temperature comparison artifacts for radiation thermometry

    SciTech Connect (OSTI)

    Teixeira, R. N. [Inmetro, Duque de Caxias, RJ (Brazil)] [Inmetro, Duque de Caxias, RJ (Brazil); Machin, G. [NPL, Teddington (United Kingdom)] [NPL, Teddington (United Kingdom); Orlando, A. [PUC-Rio, Rio de Janeiro, RJ (Brazil)] [PUC-Rio, Rio de Janeiro, RJ (Brazil)

    2013-09-11

    This paper describes the methodology and first results of the development of high temperature fixed point artifacts of unknown temperature suitable for scale comparison purposes. This study is being undertaken at the Thermal Metrology Division of Inmetro, Brazil, as part of PhD studies. In this initial phase of the study two identical cobalt carbon eutectic cells were constructed and one doped with a known amount of copper. This was an attempt to achieve a controlled change in the transition temperature of the alloy during melting. Copper was chosen due to the relatively simple phase diagram it forms with carbon and cobalt. The cobalt, in powder form, was supplied by Alfa Aesar at 99.998 % purity, and was mixed with carbon powder (1,9 % by weight) of 99.9999 % purity. Complete filling of the crucible took 6 steps and was performed in a vertical furnace with graphite heating elements, in an inert gas atmosphere. The temperature measurements were performed using a KE LP3 radiation thermometer, which was previously evaluated for spectral responsivity, linearity and size-of-source effect (SSE). During these measurements, the thermometer stability was periodically checked using a silver fixed point blackbody maintained in a three zone furnace. The main purpose of the first part of this study is to dope a series of Co-C blackbody with differing amounts of copper, in order to alter their temperatures whilst still retaining good melting plateau performance. The long-term stability of the adjusted transition temperatures will also be investigated. Other dopants will be studied as the research progresses, and thermo chemical modeling will be performed in an attempt to understand the change in temperature with dopant concentration and so help select suitable dopants in the future. The overall objective is to construct comparison artifacts that have good performance, in terms of plateau shape and long-term temperature stability, but with unknown temperatures. These can then be used as comparison artifacts with no participant, except the pilot, knowing the temperature a priori.

  2. High pressure, high current, low inductance, high reliability sealed terminals

    DOE Patents [OSTI]

    Hsu, John S. (Oak Ridge, TN) [Oak Ridge, TN; McKeever, John W. (Oak Ridge, TN) [Oak Ridge, TN

    2010-03-23

    The invention is a terminal assembly having a casing with at least one delivery tapered-cone conductor and at least one return tapered-cone conductor routed there-through. The delivery and return tapered-cone conductors are electrically isolated from each other and positioned in the annuluses of ordered concentric cones at an off-normal angle. The tapered cone conductor service can be AC phase conductors and DC link conductors. The center core has at least one service conduit of gate signal leads, diagnostic signal wires, and refrigerant tubing routed there-through. A seal material is in direct contact with the casing inner surface, the tapered-cone conductors, and the service conduits thereby hermetically filling the interstitial space in the casing interior core and center core. The assembly provides simultaneous high-current, high-pressure, low-inductance, and high-reliability service.

  3. Reactor Physics Measurements and Benchmark Specifications for Oak Ridge Highly Enriched Uranium Sphere (ORSphere)

    SciTech Connect (OSTI)

    Marshall, Margaret A.

    2014-11-04

    In the early 1970s Dr. John T. Mihalczo (team leader), J.J. Lynn, and J.R. Taylor performed experiments at the Oak Ridge Critical Experiments Facility (ORCEF) with highly enriched uranium (HEU) metal (called Oak Ridge Alloy or ORALLOY) in an effort to recreate GODIVA I results with greater accuracy than those performed at Los Alamos National Laboratory in the 1950s. The purpose of the Oak Ridge ORALLOY Sphere (ORSphere) experiments was to estimate the unreflected and unmoderated critical mass of an idealized sphere of uranium metal corrected to a density, purity, and enrichment such that it could be compared with the GODIVA I experiments. Additionally, various material reactivity worths, the surface material worth coefficient, the delayed neutron fraction, the prompt neutron decay constant, relative fission density, and relative neutron importance were all measured. The critical assembly, material reactivity worths, the surface material worth coefficient, and the delayed neutron fraction were all evaluated as benchmark experiment measurements. The reactor physics measurements are the focus of this paper; although for clarity the critical assembly benchmark specifications are briefly discussed.

  4. Reactor Physics Measurements and Benchmark Specifications for Oak Ridge Highly Enriched Uranium Sphere (ORSphere)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Marshall, Margaret A.

    2014-11-04

    In the early 1970s Dr. John T. Mihalczo (team leader), J.J. Lynn, and J.R. Taylor performed experiments at the Oak Ridge Critical Experiments Facility (ORCEF) with highly enriched uranium (HEU) metal (called Oak Ridge Alloy or ORALLOY) in an effort to recreate GODIVA I results with greater accuracy than those performed at Los Alamos National Laboratory in the 1950s. The purpose of the Oak Ridge ORALLOY Sphere (ORSphere) experiments was to estimate the unreflected and unmoderated critical mass of an idealized sphere of uranium metal corrected to a density, purity, and enrichment such that it could be compared with themore »GODIVA I experiments. Additionally, various material reactivity worths, the surface material worth coefficient, the delayed neutron fraction, the prompt neutron decay constant, relative fission density, and relative neutron importance were all measured. The critical assembly, material reactivity worths, the surface material worth coefficient, and the delayed neutron fraction were all evaluated as benchmark experiment measurements. The reactor physics measurements are the focus of this paper; although for clarity the critical assembly benchmark specifications are briefly discussed.« less

  5. HIGHLY ENRICHED URANIUM BLEND DOWN PROGRAM AT THE SAVANNAH RIVER SITE PRESENT AND FUTURE

    SciTech Connect (OSTI)

    Magoulas, V; Charles Goergen, C; Ronald Oprea, R

    2008-06-05

    The Department of Energy (DOE) and Tennessee Valley Authority (TVA) entered into an Interagency Agreement to transfer approximately 40 metric tons of highly enriched uranium (HEU) to TVA for conversion to fuel for the Browns Ferry Nuclear Power Plant. Savannah River Site (SRS) inventories included a significant amount of this material, which resulted from processing spent fuel and surplus materials. The HEU is blended with natural uranium (NU) to low enriched uranium (LEU) with a 4.95% 235U isotopic content and shipped as solution to the TVA vendor. The HEU Blend Down Project provided the upgrades needed to achieve the product throughput and purity required and provided loading facilities. The first blending to low enriched uranium (LEU) took place in March 2003 with the initial shipment to the TVA vendor in July 2003. The SRS Shipments have continued on a regular schedule without any major issues for the past 5 years and are due to complete in September 2008. The HEU Blend program is now looking to continue its success by dispositioning an additional approximately 21 MTU of HEU material as part of the SRS Enriched Uranium Disposition Project.

  6. HIGH-POWER, HIGH-EFFICIENCY FELS

    E-Print Network [OSTI]

    Sessler, A.M.

    2008-01-01

    M. Kumada, "Scaling of the FEL-ID Equations", ELF Note 128,Instability in a High-power, Short- Wavelength FEL", Proc.of the Ninth FEL" Conference, Williamsburg (1988), and

  7. High strength, high ductility low carbon steel

    DOE Patents [OSTI]

    Koo, Jayoung (Berkeley, CA); Thomas, Gareth (Berkeley, CA)

    1978-01-01

    A high strength, high ductility low carbon steel consisting essentially of iron, 0.05-0.15 wt% carbon, and 1-3 wt% silicon. Minor amounts of other constituents may be present. The steel is characterized by a duplex ferrite-martensite microstructure in a fibrous morphology. The microstructure is developed by heat treatment consisting of initial austenitizing treatment followed by annealing in the (.alpha. + .gamma.) range with intermediate quenching.

  8. Measurement of the neutron-capture cross section of 76Ge and 74Ge below 15 MeV and its relevance to 0??? decay searches of 76Ge

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bhike, Megha; Fallin, B.; Tornow, W.

    2015-02-01

    The neutron radiative-capture cross section of 76Ge was measured between 0.4 and 14.8 MeV using the activation technique. Germanium samples with the isotopic abundance of View the MathML source?86%Ge76 and View the MathML source?14%Ge74 used in the 0???0??? searches by the GERDA and Majorana Collaborations were irradiated with monoenergetic neutrons produced at eleven energies via the View the MathML sourceH3(p,n)He3, View the MathML sourceH2(d,n)He3 and View the MathML sourceH3(d,n)He4 reactions. Previously, data existed only at thermal energies and at 14 MeV. As a by-product, capture cross-section data were also obtained for 74Ge at neutron energies below 8 MeV. Indium andmore »gold foils were irradiated simultaneously for neutron fluence determination. High-resolution ?-ray spectroscopy was used to determine the ?-ray activity of the daughter nuclei of interest. For the 76Ge total capture cross section the present data are in good agreement with the TENDL-2013 model calculations and the ENDF/B-VII.1 evaluations, while for the View the MathML sourceGe74(n,?)Ge75 reaction, the present data are about a factor of two larger than predicted. It was found that the View the MathML sourceGe74(n,?)Ge75 yield in the High-Purity Germanium (HPGe) detectors used by the GERDA and Majorana Collaborations is only about a factor of two smaller than the View the MathML sourceGe76(n,?)Ge77 yield due to the larger cross section of the former reaction.« less

  9. Low Cost, High Temperature, High Ripple Current DC Bus Capacitors...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low Cost, High Temperature, High Ripple Current DC Bus Capacitors Low Cost, High Temperature, High Ripple Current DC Bus Capacitors 2010 DOE Vehicle Technologies and Hydrogen...

  10. Energy Storage Testing and Analysis High Power and High Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Testing and Analysis High Power and High Energy Development Energy Storage Testing and Analysis High Power and High Energy Development 2009 DOE Hydrogen Program and Vehicle...

  11. Large-dimension, high-ZT Thermoelectric Nanocomposites for High...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Large-dimension, high-ZT Thermoelectric Nanocomposites for High-Power High-efficiency Waste Heat Recovery for Electricity Generation Large-dimension, high-ZT Thermoelectric...

  12. High Performance Datacenter Networks

    E-Print Network [OSTI]

    Cortes, Corinna

    High Performance Datacenter Networks Architectures, Algorithms, and Opportunities #12;Synthesis architecture conferences, such as ISCA, HPCA, MICRO, and ASPLOS. High Performance Datacenter Networks Computer Architecture Daniel J. Sorin 2009 The Datacenter as a Computer: An Introduction to the Design

  13. High Performance Liquid Chromatography

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    HPLC MEASUREMENT OF POLYCYCLIC AROMATIC HYDROCARBONS IN CIGARETTE SMOKE INTRODUCTION Even thoughHPLC - 1 High Performance Liquid Chromatography HPLC MEASUREMENT OF POLYCYCLIC AROMATIC HYDROCARBONS IN CIGARETTE SMOKE Last updated: June 17, 2014 #12;HPLC - 2 High Performance Liquid Chromatography

  14. High sensitivity accelerometers are

    E-Print Network [OSTI]

    Lee, Dongwon

    metamaterial - high-permittivity dielectric resonators embedded in a low-permittivity matrix for microwave that can process light at gigahertz frequencies Tunable dielectrics for microwave communication Integrated passive components Nanotube based solar cells High frequency ultrasound for nondestruc- tive

  15. High performance systems

    SciTech Connect (OSTI)

    Vigil, M.B.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  16. High Performance Computing in

    E-Print Network [OSTI]

    Stamatakis, Alexandros

    High Performance Computing in Bioinformatics Thomas Ludwig (t.ludwig@computer.org) Ruprecht PART I: High Performance Computing Thomas Ludwig PART II: HPC Computing in Bioinformatics Alexandros #12;© Thomas Ludwig, Alexandros Stamatakis, GCB'04 3 PART I High Performance Computing Introduction

  17. High-performance combinatorial algorithms

    E-Print Network [OSTI]

    Pinar, Ali

    2003-01-01

    mathematics, and high performance computing. The numericalalgorithms on high performance computing platforms.algorithms on high performance computing platforms, which

  18. Use of Crystals for High Energy Photon Beam Linear Polarization Conversion into Circular

    E-Print Network [OSTI]

    N. Z. Akopov; A. B. Apyan; S. M. Darbinyan

    2000-02-17

    The possibility to convert the photon beam linear polarization into circular one at photon energies of hundreds GeV with the use of crystals is considered. The energy and orientation dependencies of refractive indexes are investigated in case of diamond, silicon and germanium crystal targets. To maximize the values for figure of merit, the corresponding crystal optimal orientation angles and thickness are found. The degree of circular polarization and intensity of photon beam are estimated and possibility of experimental realization is discussed.

  19. High power, high beam quality regenerative amplifier

    DOE Patents [OSTI]

    Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Livermore, CA)

    1993-01-01

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  20. High power, high beam quality regenerative amplifier

    DOE Patents [OSTI]

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  1. Fabrication of Niobium sheet for RF cavities 

    E-Print Network [OSTI]

    Balachandran, Shreyas

    2009-05-15

    This thesis investigated the microstructure and mechanical property of RRR( high purity) and RG (low purity) niobium (Nb) sheet material. RRR Nb is used in the fabrication RF cavities. Our method involves processing bulk ...

  2. MultiWave™ Automated Sorting System for Efficient Recycling

    Broader source: Energy.gov [DOE]

    The primary challenge in recycling paper has been to obtain raw material with the highest purity. Ideally, creating a paper stream sorted by purity would facilitate a high-quality end product,...

  3. Fuel Accident Condition Simulator (FACS) Furnace for Post-Irradiation Heating Tests of VHTR Fuel Compacts

    SciTech Connect (OSTI)

    Paul A Demkowicz; Paul Demkowicz; David V Laug

    2010-10-01

    Abstract –Fuel irradiation testing and post-irradiation examination are currently in progress as part of the Next Generation Nuclear Plant Fuels Development and Qualification Program. The PIE campaign will include extensive accident testing of irradiated very high temperature reactor fuel compacts to verify fission product retention characteristics at high temperatures. This work will be carried out at both the Idaho National Laboratory (INL) and the Oak Ridge National Laboratory, beginning with accident tests on irradiated fuel from the AGR-1 experiment in 2010. A new furnace system has been designed, built, and tested at INL to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000°C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, Eu, and I) and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator (FACS) furnace system, as well as preliminary system calibration results.

  4. NID Copper Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Zhu, Zihua

    2011-09-12

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). This experiment requires the use of germanium isotopically enriched in 76Ge. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one under development at Nonlinear Ion Dynamics (NID), will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.

  5. The Design of an Ultra-Low Background Thermosyphon for the Majorana Demonstrator

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Busch, Matthew; Daniels, Randy; Fast, James E.; Green, Matthew P.; Reid, Douglas J.

    2013-05-01

    The MAJORANA DEMONSTRATOR (MJD) is an ultra-low background neutrinoless double-beta decay (0???) experiment that will deploy up to 40 kg of high purity germanium detectors (HPGe). The goal of this experiment is to demonstrate the feasibility of building a detector array with less than 1 event/ton-year in a 4 keV region of interest around the 0??? signal. HPGe diodes, when used as ionizing radiation detectors, need to be maintained at a temperature close to that of liquid nitrogen (77 K). This work describes the R&D results of a cryogenic system capable of meeting the requirements of low background and the cooling capacity required to successfully operate such a detector system. The MJD germanium detector modules will operate at liquid nitrogen temperature to provide adequate cooling for a full range of HPGe impurity concentrations. This paper shows the experimental results obtained using a two-phase horizontal thermosyphon using liquid nitrogen as the MJD’s cooling system. The cold test shows that the proposed thermosyphon has sufficient cooling power to handle the heat load of an MJD module. Results for the temperature gradient across the thermosyphon, cooling capacity, and design considerations demonstrate that the thermosyphon can effectively remove the calculated heat load of each module of the experiment. The thermosyphon will be bolted to a cold plate from which detector strings will hang. The thermal conductivity of a mockup of the MJD bolted thermal joint is experimentally determined to be below 0.1 K/W.

  6. Highly directional thermal emitter

    DOE Patents [OSTI]

    Ribaudo, Troy; Shaner, Eric A; Davids, Paul; Peters, David W

    2015-03-24

    A highly directional thermal emitter device comprises a two-dimensional periodic array of heavily doped semiconductor structures on a surface of a substrate. The array provides a highly directional thermal emission at a peak wavelength between 3 and 15 microns when the array is heated. For example, highly doped silicon (HDSi) with a plasma frequency in the mid-wave infrared was used to fabricate nearly perfect absorbing two-dimensional gratings structures that function as highly directional thermal radiators. The absorption and emission characteristics of the HDSi devices possessed a high degree of angular dependence for infrared absorption in the 10-12 micron range, while maintaining high reflectivity of solar radiation (.about.64%) at large incidence angles.

  7. High voltage coaxial switch

    DOE Patents [OSTI]

    Rink, John P. (Los Alamos, NM)

    1983-07-19

    A coaxial high voltage, high current switch having a solid cylindrical cold cathode coaxially surrounded by a thin hollow cylindrical inner electrode and a larger hollow cylindrical outer electrode. A high voltage trigger between the cathode and the inner electrode causes electrons to be emitted from the cathode and flow to the inner electrode preferably through a vacuum. Some of the electrons penetrate the inner electrode and cause a volumetric discharge in the gas (which may be merely air) between the inner and outer electrodes. The discharge provides a low impedance path between a high voltage charge placed on the outer electrode and a load (which may be a high power laser) coupled to the inner electrode. For high repetition rate the gas between the inner and outer electrodes may be continuously exchanged or refreshed under pressure.

  8. High voltage coaxial switch

    DOE Patents [OSTI]

    Rink, J.P.

    1983-07-19

    A coaxial high voltage, high current switch having a solid cylindrical cold cathode coaxially surrounded by a thin hollow cylindrical inner electrode and a larger hollow cylindrical outer electrode. A high voltage trigger between the cathode and the inner electrode causes electrons to be emitted from the cathode and flow to the inner electrode preferably through a vacuum. Some of the electrons penetrate the inner electrode and cause a volumetric discharge in the gas (which may be merely air) between the inner and outer electrodes. The discharge provides a low impedance path between a high voltage charge placed on the outer electrode and a load (which may be a high power laser) coupled to the inner electrode. For high repetition rate the gas between the inner and outer electrodes may be continuously exchanged or refreshed under pressure. 3 figs.

  9. High pressure and high temperature apparatus

    DOE Patents [OSTI]

    Voronov, Oleg A.

    2005-09-13

    A design for high pressure/high temperature apparatus and reaction cell to achieve .about.30 GPa pressure in .about.1 cm volume and .about.100 GPa pressure in .about.1 mm volumes and 20-5000.degree. C. temperatures in a static regime. The device includes profiled anvils (28) action on a reaction cell (14, 16) containing the material (26) to be processed. The reaction cell includes a heater (18) surrounded by insulating layers and screens. Surrounding the anvils are cylindrical inserts and supporting rings (30-48) whose hardness increases towards the reaction cell. These volumes may be increased considerably if applications require it, making use of presses that have larger loading force capability, larger frames and using larger anvils.

  10. High output lamp with high brightness

    DOE Patents [OSTI]

    Kirkpatrick, Douglas A. (Great Falls, VA); Bass, Gary K. (Mt. Airy, MD); Copsey, Jesse F. (Germantown, MD); Garber, Jr., William E. (Poolesville, MD); Kwong, Vincent H. (Vancouver, CA); Levin, Izrail (Silver Spring, MD); MacLennan, Donald A. (Gaithersburg, MD); Roy, Robert J. (Frederick, MD); Steiner, Paul E. (Olney, MD); Tsai, Peter (Olney, MD); Turner, Brian P. (Damascus, MD)

    2002-01-01

    An ultra bright, low wattage inductively coupled electrodeless aperture lamp is powered by a solid state RF source in the range of several tens to several hundreds of watts at various frequencies in the range of 400 to 900 MHz. Numerous novel lamp circuits and components are disclosed including a wedding ring shaped coil having one axial and one radial lead, a high accuracy capacitor stack, a high thermal conductivity aperture cup and various other aperture bulb configurations, a coaxial capacitor arrangement, and an integrated coil and capacitor assembly. Numerous novel RF circuits are also disclosed including a high power oscillator circuit with reduced complexity resonant pole configuration, parallel RF power FET transistors with soft gate switching, a continuously variable frequency tuning circuit, a six port directional coupler, an impedance switching RF source, and an RF source with controlled frequency-load characteristics. Numerous novel RF control methods are disclosed including controlled adjustment of the operating frequency to find a resonant frequency and reduce reflected RF power, controlled switching of an impedance switched lamp system, active power control and active gate bias control.

  11. High Energy Physics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Large Scale Production Computing and Storage Requirements for High Energy Physics: Target 2017 HEPlogo.jpg The NERSC Program Requirements Review "Large Scale Computing and Storage...

  12. High Energy Physics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientific Computing Research Basic Energy Sciences Biological and Environmental Research Fusion Energy Sciences High Energy Physics Nuclear Physics Advanced Scientific Computing...

  13. High coking value pitch

    SciTech Connect (OSTI)

    Miller, Douglas J.; Chang, Ching-Feng; Lewis, Irwin C.; Lewis, Richard T.

    2014-06-10

    A high coking value pitch prepared from coal tar distillate and has a low softening point and a high carbon value while containing substantially no quinoline insolubles is disclosed. The pitch can be used as an impregnant or binder for producing carbon and graphite articles.

  14. High power, high frequency, vacuum flange

    DOE Patents [OSTI]

    Felker, B.; McDaniel, M.R.

    1993-03-23

    An improved waveguide flange is disclosed for high power operation that helps prevent arcs from being initiated at the junctions between waveguide sections. The flanges at the end of the waveguide sections have counter bores surrounding the waveguide tubes. When the sections are bolted together the counter bores form a groove that holds a fully annealed copper gasket. Each counterbore has a beveled step that is specially configured to insure the gasket forms a metal-to-metal vacuum seal without gaps or sharp edges. The resultant inner surface of the waveguide is smooth across the junctions between waveguide sections, and arcing is prevented.

  15. Response of High-Tc Superconductor Metamaterials to High Intensity...

    Office of Scientific and Technical Information (OSTI)

    Conference: Response of High-Tc Superconductor Metamaterials to High Intensity THz Radiation Citation Details In-Document Search Title: Response of High-Tc Superconductor...

  16. HIGH-FIDELITY RADIO ASTRONOMICAL POLARIMETRY USING A MILLISECOND PULSAR AS A POLARIZED REFERENCE SOURCE

    SciTech Connect (OSTI)

    Van Straten, W.

    2013-01-15

    A new method of polarimetric calibration is presented in which the instrumental response is derived from regular observations of PSR J0437-4715 based on the assumption that the mean polarized emission from this millisecond pulsar remains constant over time. The technique is applicable to any experiment in which high-fidelity polarimetry is required over long timescales; it is demonstrated by calibrating 7.2 years of high-precision timing observations of PSR J1022+1001 made at the Parkes Observatory. Application of the new technique followed by arrival time estimation using matrix template matching yields post-fit residuals with an uncertainty-weighted standard deviation of 880 ns, two times smaller than that of arrival time residuals obtained via conventional methods of calibration and arrival time estimation. The precision achieved by this experiment yields the first significant measurements of the secular variation of the projected semimajor axis, the precession of periastron, and the Shapiro delay; it also places PSR J1022+1001 among the 10 best pulsars regularly observed as part of the Parkes Pulsar Timing Array (PPTA) project. It is shown that the timing accuracy of a large fraction of the pulsars in the PPTA is currently limited by the systematic timing error due to instrumental polarization artifacts. More importantly, long-term variations of systematic error are correlated between different pulsars, which adversely affects the primary objectives of any pulsar timing array experiment. These limitations may be overcome by adopting the techniques presented in this work, which relax the demand for instrumental polarization purity and thereby have the potential to reduce the development cost of next-generation telescopes such as the Square Kilometre Array.

  17. Time-resolved measurements of the hot-electron population in ignition-scale experiments on the National Ignition Facility (invited)

    SciTech Connect (OSTI)

    Hohenberger, M. Stoeckl, C.; Albert, F.; Palmer, N. E.; Döppner, T.; Divol, L.; Dewald, E. L.; Bachmann, B.; MacPhee, A. G.; LaCaille, G.; Bradley, D. K.; Lee, J. J.

    2014-11-15

    In laser-driven inertial confinement fusion, hot electrons can preheat the fuel and prevent fusion-pellet compression to ignition conditions. Measuring the hot-electron population is key to designing an optimized ignition platform. The hot electrons in these high-intensity, laser-driven experiments, created via laser-plasma interactions, can be inferred from the bremsstrahlung generated by hot electrons interacting with the target. At the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)], the filter-fluorescer x-ray (FFLEX) diagnostic–a multichannel, hard x-ray spectrometer operating in the 20–500 keV range–has been upgraded to provide fully time-resolved, absolute measurements of the bremsstrahlung spectrum with ?300 ps resolution. Initial time-resolved data exhibited significant background and low signal-to-noise ratio, leading to a redesign of the FFLEX housing and enhanced shielding around the detector. The FFLEX x-ray sensitivity was characterized with an absolutely calibrated, energy-dispersive high-purity germanium detector using the high-energy x-ray source at NSTec Livermore Operations over a range of K-shell fluorescence energies up to 111 keV (U K{sub ?}). The detectors impulse response function was measured in situ on NIF short-pulse (?90 ps) experiments, and in off-line tests.

  18. Background Radiation Survey of the Radiological/Nuclear Countermeasures Test and Evaluation Center

    SciTech Connect (OSTI)

    Colin Okada

    2010-09-16

    In preparation for operations at the Radiological/Nuclear Countermeasures Test and Evaluation Complex (Rad/NucCTEC), the Department of Homeland Security Domestic Nuclear Detection Office (DHS/DNDO) requested that personnel from the Remote Sensing Laboratory (RSL) conduct a survey of the present radiological conditions at the facility. The measurements consist of the exposure rate from a high-pressure ion chamber (HPIC), high-resolution spectra from a high-purity germanium (HPGe) system in an in situ configuration, and low-resolution spectra from a sodium iodide (NaI) detector in a radiation detection backpack. Measurements with these systems were collected at discrete locations within the facility. Measurements were also collected by carrying the VECTOR backpack throughout the complex to generate a map of the entire area. The area was also to be surveyed with the Kiwi (an array of eight-2-inch x 4-inch x 16-inch NaI detectors) from the Aerial Measuring Systems; however, conflicts with test preparation activities at the site prevented this from being accomplished.

  19. Atmospheric deposition of {sup 7}Be by rain events, incentral Argentina

    SciTech Connect (OSTI)

    Ayub, J. Juri; Velasco, H.; Rizzotto, M. [Grupo de Estudios Ambientales. Instituto de Matematica Aplicada San Luis. Universidad National de San Luis--CONICET. Ejercito de los Andes 950. Argentina (Argentina); Di Gregorio, D. E.; Huck, H. [Departamento de Fisica, Comision National de Energia Atomica, Av. Gral. Paz 1499, 1650 San Martin, Provincia de Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad National de San Martin. Martin de Irigoyen 3100, 1650 San Martin, Provincia de Buenos Aires, Argentina. (Argentina)

    2008-08-07

    Beryllium-7 is a natural radionuclide that enters into the ecosystems through wet and dry depositions and has numerous environmental applications in terrestrial and aquatic ecosystems. Atmospheric wet deposition of {sup 7}Be was measured in central Argentina. Rain traps were installed (1 m above ground) and individual rain events have been collected. Rain samples were filtered and analyzed by gamma spectrometry. The gamma counting was undertaken using a 40%-efficient p-type coaxial intrinsic high-purity natural germanium crystal built by Princeton Gamma-Tech. The cryostat was made from electroformed high-purity copper using ultralow-background technology. The detector was surrounded by 50 cm of lead bricks to provide shielding against radioactive background. The detector gamma efficiency was determined using a water solution with known amounts of chemical compounds containing long-lived naturally occurring radioisotopes, {sup 176}Lu, {sup 138}La and {sup 40}K. Due to the geometry of the sample and its position close to the detector, the efficiency points from the {sup 176}Lu decay, had to be corrected for summing effects. The measured samples were 400 ml in size and were counted curing one day. The {sup 7}Be detection limit for the present measurements was as low as 0.2 Bq l{sup -1}. Thirty two rain events were sampled and analyzed (November 2006-May 2007). The measured values show that the events corresponding to low rainfall (<20 mm) are characterized by significantly higher activity concentrations (Bq l{sup -1}). The activity concentration of each individual event varied from 0.8 to 3.5 Bq l{sup -1}, while precipitations varied between 4 and 70 mm. The integrated activity by event of {sup 7}Be was fitted with a model that takes into account the precipitation amount and the elapsed time between two rain events. The integrated activities calculated with this model show a good agreement with experimental values.

  20. RECHARGEABLE HIGH-TEMPERATURE BATTERIES

    E-Print Network [OSTI]

    Cairns, Elton J.

    2014-01-01

    F. Eshman, High-Performance Batteries for Electric-VehicleS. Sudar, High Performance Batteries for Electric-VehicleHIGH-TEMPERATURE BATTERIES Elton J. Cairns January 1981 TWO-

  1. Sandia Energy - High Performance Computing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    High Performance Computing Home Energy Research Advanced Scientific Computing Research (ASCR) High Performance Computing High Performance Computingcwdd2015-03-18T21:41:24+00:00...

  2. Sandia Energy - High Pressure Chemistry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    High Pressure Chemistry Home Transportation Energy Predictive Simulation of Engines Combustion Chemistry Combustion Kinetics High Pressure Chemistry High Pressure ChemistryAshley...

  3. High pressure counterflow CHF.

    E-Print Network [OSTI]

    Walkush, Joseph Patrick

    1975-01-01

    This is a report of the experimental results of a program in countercurrent flow critical heat flux. These experiments were performed with Freon 113 at 200 psia in order to model a high pressure water system. An internally ...

  4. High pressure furnace

    DOE Patents [OSTI]

    Morris, D.E.

    1993-09-14

    A high temperature high pressure furnace has a hybrid partially externally heated construction. A metallic vessel fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum)). The disclosed alloy is fabricated into 11/4 or 2 inch, 32 mm or 50 mm bar stock and has a length of about 22 inches, 56 cm. This bar stock has an aperture formed therein to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the vessel is provided with a small blind aperture into which a thermocouple can be inserted. The closed end of the vessel is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior. 19 figures.

  5. Using High Performance Libraries

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    by the QPI (Quick Path Interconnect) links). Using the QPI to simulate the slow memory (DDR memory) while using the memory on the near socket as the high bandwidth memory (MCDRAM...

  6. High pressure furnace

    DOE Patents [OSTI]

    Morris, Donald E. (Kensington, CA)

    1993-01-01

    A high temperature high pressure furnace has a hybrid partially externally heated construction. A metallic vessel fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 or 2 inch, 32 mm or 50 mm bar stock and has a length of about 22 inches, 56 cm. This bar stock has an aperture formed therein to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the vessel is provided with a small blind aperture into which a thermocouple can be inserted. The closed end of the vessel is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior.

  7. High-Temperature Superconductivity

    ScienceCinema (OSTI)

    Peter Johnson

    2010-01-08

    Like astronomers tweaking images to gain a more detailed glimpse of distant stars, physicists at Brookhaven National Laboratory have found ways to sharpen images of the energy spectra in high-temperature superconductors ? materials that carry electrical c

  8. High pressure oxygen furnace

    DOE Patents [OSTI]

    Morris, Donald E. (Kensington, CA)

    1992-01-01

    A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior.

  9. High pressure oxygen furnace

    DOE Patents [OSTI]

    Morris, D.E.

    1992-07-14

    A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized, the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior. 5 figs.

  10. High-Speed Photography

    SciTech Connect (OSTI)

    Paisley, D.L.; Schelev, M.Y.

    1998-08-01

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) {copyright} {ital 1998 Society of Photo-Optical Instrumentation Engineers.}

  11. High Performance Sustainable Building

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2011-11-09

    This Guide provides approaches for implementing the High Performance Sustainable Building (HPSB) requirements of DOE Order 413.3B, Program and Project Management for the Acquisition of Capital Assets. Supersedes DOE G 413.3-6.

  12. Creating high performance enterprises

    E-Print Network [OSTI]

    Stanke, Alexis K. (Alexis Kristen), 1977-

    2006-01-01

    How do enterprises successfully conceive, design, deliver, and operate large-scale, engineered systems? These large-scale projects often involve high complexity, significant technical challenges, a large number of diverse ...

  13. High-temperature sensor

    DOE Patents [OSTI]

    Not Available

    1981-01-29

    A high temperature sensor is described which includes a pair of electrical conductors separated by a mass of electrical insulating material. The insulating material has a measurable resistivity within the sensor that changes in relation to the temperature of the insulating material within a high temperature range (1000 to 2000/sup 0/K). When required, the sensor can be encased within a ceramic protective coating.

  14. High efficiency incandescent lighting

    DOE Patents [OSTI]

    Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin

    2014-09-02

    Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.

  15. High conductivity composite metal

    DOE Patents [OSTI]

    Zhou, R.; Smith, J.L.; Embury, J.D.

    1998-01-06

    Electrical conductors and methods of producing them are disclosed, where the conductors possess both high strength and high conductivity. Conductors are comprised of carbon steel and a material chosen from a group consisting of copper, nickel, silver, and gold. Diffusion barriers are placed between these two materials. The components of a conductor are assembled and then the assembly is subjected to heat treating and mechanical deformation steps. 10 figs.

  16. High temperature pressure gauge

    DOE Patents [OSTI]

    Echtler, J. Paul (Pittsburgh, PA); Scandrol, Roy O. (Library, PA)

    1981-01-01

    A high temperature pressure gauge comprising a pressure gauge positioned in fluid communication with one end of a conduit which has a diaphragm mounted in its other end. The conduit is filled with a low melting metal alloy above the diaphragm for a portion of its length with a high temperature fluid being positioned in the remaining length of the conduit and in the pressure gauge.

  17. High Risk Plan

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12,ExecutiveFinancing ProgramsDepartment of¡High HIGH PERFORMANCE

  18. High Burnup Effects Program

    SciTech Connect (OSTI)

    Barner, J.O.; Cunningham, M.E.; Freshley, M.D.; Lanning, D.D.

    1990-04-01

    This is the final report of the High Burnup Effects Program (HBEP). It has been prepared to present a summary, with conclusions, of the HBEP. The HBEP was an international, group-sponsored research program managed by Battelle, Pacific Northwest Laboratories (BNW). The principal objective of the HBEP was to obtain well-characterized data related to fission gas release (FGR) for light water reactor (LWR) fuel irradiated to high burnup levels. The HBEP was organized into three tasks as follows: Task 1 -- high burnup effects evaluations; Task 2 -- fission gas sampling; and Task 3 -- parameter effects study. During the course of the HBEP, a program that extended over 10 years, 82 fuel rods from a variety of sources were characterized, irradiated, and then examined in detail after irradiation. The study of fission gas release at high burnup levels was the principal objective of the program and it may be concluded that no significant enhancement of fission gas release at high burnup levels was observed for the examined rods. The rim effect, an as yet unquantified contributor to athermal fission gas release, was concluded to be the one truly high-burnup effect. Though burnup enhancement of fission gas release was observed to be low, a full understanding of the rim region and rim effect has not yet emerged and this may be a potential area of further research. 25 refs., 23 figs., 4 tabs.

  19. Thermoelectrics Partnership: High Performance Thermoelectric...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Performance Thermoelectric Waste Heat Recovery System Based on Zintl Phase Materials with Embedded Nanoparticles Thermoelectrics Partnership: High Performance Thermoelectric...

  20. High surface area, high permeability carbon monoliths

    SciTech Connect (OSTI)

    Lagasse, R.R.; Schroeder, J.L. [Sandia National Labs., Albuquerque, NM (United States). Organic Materials Processing Dept.

    1994-12-31

    The goal of this work is to prepare carbon monoliths having precisely tailored pore size distribution. Prior studies have demonstrated that poly(acrylonitrile) can be processed into a precursor having tailored macropore structure. Since the macropores were preserved during pyrolysis, this synthetic process provided a route to porous carbon having macropores with size =0.1 to 10{mu}m. No micropores of size <2 nm could be detected in the carbon, however, by nitrogen adsorption. In the present work, the authors have processed a different polymer, poly(vinylidene chloride) into a macroporous precursor, Pyrolysis produced carbon monoliths having macropores derived from the polymer precursor as well as extensive microporosity produced during the pyrolysis of the polymer. One of these carbons had BET surface area of 1,050 m{sup 2}/g and about 1.2 cc/g total pore volume, with about 1/3 of the total pore volume in micropores and the remainder in 1{mu}m macropores. No mesopores in the intermediate size range could be detected by nitrogen adsorption. Carbon materials having high surface area as well as micron size pores have potential applications as electrodes for double layer supercapacitors containing liquid electrolyte, or as efficient media for performing chemical separations.

  1. Enriched $^{82}$Se for the LUCIFER experiment

    E-Print Network [OSTI]

    Beeman, J W; Benetti, P; Cardani, L; Casali, N; Chiesa, D; Clemenza, M; Dafinei, I; Di Domizio, S; Ferroni, F; Gironi, L; Giuliani, A; Gotti, C; Laubenstein, M; Maino, M; Nagorny, S; Nisi, S; Nones, C; Orio, F; Pagnanini, L; Pattavina, L; Pessina, G; Piperno, G; Pirro, S; Previtali, E; Rusconi, C; Schäffner, K; Tomei, C; Vignati, M

    2015-01-01

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of $^{82}$Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched $^{82}$Se is used as decay isotope. The radiopurity of the initial components employed for manufacturing crystals, that can be operated as bolometers, is crucial for achieving a null background level in the region of interest for double-beta decay investigations. In this work, we evaluated the radioactive content in 2.5 kg of 96.3% enriched $^{82}$Se metal, measured with a high-purity germanium detector at the Gran Sasso deep underground laboratory. The limits on internal contaminations of primordial decay chain elements of $^{232}$Th, $^{238}$U and $^{235}$U are respectively: $<$61 $\\mu$Bq/kg, $<$110 $\\mu$Bq/kg and $<$74 $\\mu$Bq/kg at 90% C.L.. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the $^{82}$...

  2. Enriched $^{82}$Se for the LUCIFER experiment

    E-Print Network [OSTI]

    J. W. Beeman; F. Bellini; P. Benetti; L. Cardani; N. Casali; D. Chiesa; M. Clemenza; I. Dafinei; S. Di Domizio; F. Ferroni; L. Gironi; A. Giuliani; C. Gotti; M. Laubenstein; M. Maino; S. Nagorny; S. Nisi; C. Nones; F. Orio; L. Pagnanini; L. Pattavina; G. Pessina; G. Piperno; S. Pirro; E. Previtali; C. Rusconi; K. Schäffner; C. Tomei; M. Vignati

    2015-08-07

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of $^{82}$Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched $^{82}$Se is used as decay isotope. The radiopurity of the initial components employed for manufacturing crystals, that can be operated as bolometers, is crucial for achieving a null background level in the region of interest for double-beta decay investigations. In this work, we evaluated the radioactive content in 2.5 kg of 96.3% enriched $^{82}$Se metal, measured with a high-purity germanium detector at the Gran Sasso deep underground laboratory. The limits on internal contaminations of primordial decay chain elements of $^{232}$Th, $^{238}$U and $^{235}$U are respectively: $<$61 $\\mu$Bq/kg, $<$110 $\\mu$Bq/kg and $<$74 $\\mu$Bq/kg at 90% C.L.. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the $^{82}$Se allowed us to establish the most stringent lower limits on the half-lives of the double-beta decay of $^{82}$Se to 0$^+_1$, 2$^+_2$ and 2$^+_1$ excited states of $^{82}$Kr of 3.4$\\cdot$10$^{22}$ y, 1.3$\\cdot$10$^{22}$ y and 1.0$\\cdot$10$^{22}$ y, respectively, with a 90% C.L..

  3. Synchrotron-based X-ray fluorescence imaging and elemental mapping from biological samples

    SciTech Connect (OSTI)

    D Rao; M Swapna; R Cesareo; A Brunetti; T Akatsuka; T Yuasa; T Takeda; G Gigante

    2011-12-31

    The present study utilized the new hard X-ray microspectroscopy beamline facility, X27A, available at NSLS, BNL, USA, for elemental mapping. This facility provided the primary beam in a small spot of the order of {approx}10 {mu}m, for focussing. With this spatial resolution and high flux throughput, the synchrotron-based X-ray fluorescent intensities for Mn, Fe, Zn, Cr, Ti and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector. The sample is scanned in a 'step-and-repeat' mode for fast elemental mapping measurements and generated elemental maps at 8, 10 and 12 keV, from a small animal shell (snail). The accumulated trace elements, from these biological samples, in small areas have been identified. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other elements.

  4. Deconvolution of mixed gamma emitters using peak parameters

    SciTech Connect (OSTI)

    Gadd, Milan S; Garcia, Francisco; Magadalena, Vigil M

    2011-01-14

    When evaluating samples containing mixtures of nuclides using gamma spectroscopy the situation sometimes arises where the nuclides present have photon emissions that cannot be resolved by the detector. An example of this is mixtures of {sup 241}Am and plutonium that have L x-ray emissions with slightly different energies which cannot be resolved using a high-purity germanium detector. It is possible to deconvolute the americium L x-rays from those plutonium based on the {sup 241}Am 59.54 keV photon. However, this requires accurate knowledge of the relative emission yields. Also, it often results in high uncertainties in the plutonium activity estimate due to the americium yields being approximately an order of magnitude greater than those for plutonium. In this work, an alternative method of determining the relative fraction of plutonium in mixtures of {sup 241}Am and {sup 239}Pu based on L x-ray peak location and shape parameters is investigated. The sensitivity and accuracy of the peak parameter method is compared to that for conventional peak decovolution.

  5. High pressure melt ejection

    SciTech Connect (OSTI)

    Tarbell, W.W.; Brockmann, J.E.; Pilch, M.

    1983-01-01

    Recent probabilistic risk assessments have identified the potential for reactor pressure vessel failure while the reactor coolant system is at elevated pressure. The analyses postulate that the blowdown of steam and hydrogen into the reactor cavity will cause the core material to be swept from the cavity region into the containment building. The High Pressure Melt Streaming (HIPS) program is an experimental study of the high pressure ejection of molten material and subsequent interactions within a concrete cavity. The program focuses on using prototypic system conditions and scaled models of reactor geometries to accurately simulate the ex-vessel processes during high-pressure accident sequences. Scaling analyses of the experiment show that the criteria established for core debris removal from the cavity are met or exceeded. Tests are performed at two scales, representing 1/10th and 1/20th linear reproductions of the Zion reactor plant. Results of the 1/20th scale tests are presented.

  6. High resolution data acquisition

    DOE Patents [OSTI]

    Thornton, G.W.; Fuller, K.R.

    1993-04-06

    A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock, pulse train, and analog circuitry for generating a triangular wave synchronously with the pulse train (as seen in diagram on patent). The triangular wave has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter counts the clock pulse train during the interval to form a gross event interval time. A computer then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

  7. High Metallicity LGRB Hosts

    E-Print Network [OSTI]

    Graham, J F; Levesque, E M; Kewley, L J; Tanvir, N R; Levan, A J; Patel, S K; Misra, K; Huang, K -H; Reichart, D E; Nysewander, M; Schady, P

    2015-01-01

    We present our imaging and spectroscopic observations of the host galaxies of two dark long bursts with anomalously high metallicities, LGRB 051022 and LGRB 020819B, which in conjunction with another LGRB event with an optical afterglow comprise the three LGRBs with high metallicity host galaxies in the Graham & Fruchter (2013) sample. In Graham & Fruchter (2013), we showed that LGRBs exhibit a strong and apparently intrinsic preference for low metallicity environments (12+log(O/H) & redshift. This is surprising: even among a preselected sample of high metallicity LGRBs, were the metal aversion to remain in effect for these objects, we would expect their metallicity to still be lower than the typical metallicity for the galaxies at that luminosity and redshift. Therefore we deduce that it...

  8. High resolution data acquisition

    DOE Patents [OSTI]

    Thornton, Glenn W. (Los Alamos, NM); Fuller, Kenneth R. (Los Alamos, NM)

    1993-01-01

    A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock (38) pulse train (37) and analog circuitry (44) for generating a triangular wave (46) synchronously with the pulse train (37). The triangular wave (46) has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter (18, 32) forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter (26) counts the clock pulse train (37) during the interval to form a gross event interval time. A computer (52) then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

  9. High-energy detector

    DOE Patents [OSTI]

    Bolotnikov, Aleksey E. (South Setauket, NY); Camarda, Giuseppe (Farmingville, NY); Cui, Yonggang (Upton, NY); James, Ralph B. (Ridge, NY)

    2011-11-22

    The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

  10. High strength alloys

    DOE Patents [OSTI]

    Maziasz, Phillip James; Shingledecker, John Paul; Santella, Michael Leonard; Schneibel, Joachim Hugo; Sikka, Vinod Kumar; Vinegar, Harold J.; John, Randy Carl; Kim, Dong Sub

    2012-06-05

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tublar that is at least partially made from a material containing at least one of the metal alloys.

  11. High strength alloys

    DOE Patents [OSTI]

    Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX

    2010-08-31

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.

  12. Highly Effective Actions

    E-Print Network [OSTI]

    John H. Schwarz

    2013-11-22

    It is conjectured that the world-volume action of a probe D3-brane in an $AdS_5 \\times S^5$ background of type IIB superstring theory, with one unit of flux, can be reinterpreted as the exact effective action (or highly effective action) for U(2), ${\\cal N} = 4$ super Yang-Mills theory on the Coulomb branch. An analogous conjecture for $U(2)_k \\times U(2)_{-k} $ ABJM theory is also presented. The main evidence supporting these conjectures is that the brane actions have all of the expected symmetries and dualities. Highly effective actions have general coordinate invariance, even though they describe nongravitational theories.

  13. High-Tc Superconductor

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHigh energy neutronHigh-Pressure MOF ResearchEnergyDonghui Lu,

  14. High-fidelity Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHigh energy neutronHigh-Pressure MOFElectricityBiofuel

  15. High-speed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHigh energy neutronHigh-PressureLaboratoryspeed three-wave

  16. High-␤,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHigh energy neutronHigh-PressureLaboratoryspeed

  17. Concepts for High Availability in Scientific High-End Computing

    E-Print Network [OSTI]

    Engelmann, Christian

    Concepts for High Availability in Scientific High-End Computing Christian Engelmann 1,2 and Stephen 2 Department of Computer Science The University of Reading, Reading, UK High Availability and Stephen L. Scott, Oak Ridge National Laboratory Concepts for High Availability in Scientific High

  18. Systems Analyses of Advanced Brayton Cycles For High Efficiency Zero Emission Plants

    SciTech Connect (OSTI)

    A. D. Rao; J. Francuz; H. Liao; A. Verma; G. S. Samuelsen

    2006-11-01

    Table 1 shows that the systems efficiency, coal (HHV) to power, is 35%. Table 2 summarizes the auxiliary power consumption within the plant. Thermoflex was used to simulate the power block and Aspen Plus the balance of plant. The overall block flow diagram is presented in Figure A1.3-1 and the key unit process flow diagrams are shown in subsequent figures. Stream data are given in Table A1.3-1. Equipment function specifications are provided in Tables A1.3-2 through 17. The overall plant scheme consists of a cryogenic air separation unit supplying 95% purity O{sub 2} to GE type high pressure (HP) total quench gasifiers. The raw gas after scrubbing is treated in a sour shift unit to react the CO with H{sub 2}O to form H{sub 2} and CO{sub 2}. The gas is further treated to remove Hg in a sulfided activated carbon bed. The syngas is desulfurized and decarbonized in a Selexol acid gas removal unit and the decarbonized syngas after humidification and preheat is fired in GE 7H type steam cooled gas turbines. Intermediate pressure (IP) N{sub 2} from the ASU is also supplied to the combustors of the gas turbines as additional diluent for NOx control. A portion of the air required by the ASU is extracted from the gas turbines. The plant consists of the following major process units: (1) Air Separation Unit (ASU); (2) Gasification Unit; (3) CO Shift/Low Temperature Gas Cooling (LTGC) Unit; (4) Acid Gas Removal Unit (AGR) Unit; (5) Fuel Gas Humidification Unit; (6) Carbon Dioxide Compression/Dehydration Unit; (7) Claus Sulfur Recovery/Tail Gas Treating Unit (SRU/TGTU); and (8) Power Block.

  19. High Energy Photoproduction

    E-Print Network [OSTI]

    J. M. Butterworth; M. Wing

    2005-09-15

    The experimental and phenomenological status of high energy photoproduction is reviewed. Topics covered include the structure of the photon, production of jets, heavy flavours and prompt photons, rapidity gaps, energy flow and underlying events. The results are placed in the context of the current understanding of QCD, with particular application to present and future hadron and lepton colliders.

  20. High temperature storage battery

    SciTech Connect (OSTI)

    Sammells, A.F.

    1988-06-07

    A high temperature electrochemical cell is described comprising: a solid-state divalent cation conducting electrolyte; a positive electrode in contact with the electrolyte; a solid-state negative electrode contacting a divalent cation conducting molten salt mediating agent providing ionic mediation between the solid-state negative electrode and the solid-state electrolyte.

  1. High Power Cryogenic Targets

    SciTech Connect (OSTI)

    Gregory Smith

    2011-08-01

    The development of high power cryogenic targets for use in parity violating electron scattering has been a crucial ingredient in the success of those experiments. As we chase the precision frontier, the demands and requirements for these targets have grown accordingly. We discuss the state of the art, and describe recent developments and strategies in the design of the next generation of these targets.

  2. High Temperature ESP Monitoring

    Broader source: Energy.gov [DOE]

    The purpose of the High Temperature ESP Monitoring project is to develop a down-hole monitoring system to be used in wells with bottom hole temperature up to 300 °C for measuring motor temperature; pump discharge pressure; and formation temperature and pressure.

  3. High speed door assembly

    DOE Patents [OSTI]

    Shapiro, C.

    1993-04-27

    A high speed door assembly is described, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  4. High speed door assembly

    DOE Patents [OSTI]

    Shapiro, Carolyn (Idaho Falls, ID)

    1993-01-01

    A high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  5. High expression Zymomonas promoters

    DOE Patents [OSTI]

    Viitanen, Paul V. (West Chester, PA); Tao, Luan (Havertown, PA); Zhang, Yuying (New Hope, PA); Caimi, Perry G. (Kennett Square, PA); McCole, Laura (East Fallowfield, PA): Zhang, Min (Lakewood, CO); Chou, Yat-Chen (Lakewood, CO); McCutchen, Carol M. (Wilmington, DE); Franden, Mary Ann (Centennial, CO)

    2011-08-02

    Identified are mutants of the promoter of the Z. mobilis glyceraldehyde-3-phosphate dehydrogenase gene, which direct improved expression levels of operably linked heterologous nucleic acids. These are high expression promoters useful for expression of chimeric genes in Zymomonas, Zymobacter, and other related bacteria.

  6. High Performance Sustainable Building

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2008-06-20

    The guide supports DOE O 413.3A and provides useful information on the incorporation of high performance sustainable building principles into building-related General Plant Projects and Institutional General Plant Projects at DOE sites. Canceled by DOE G 413.3-6A. Does not cancel other directives.

  7. CSTI high capacity power

    SciTech Connect (OSTI)

    Winter, J.M.

    1994-09-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase I of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY88, the Advanced Technology Program was incorporated into NASA`s new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed.

  8. High Selectivity Oxygen Delignification

    SciTech Connect (OSTI)

    Arthur J. Ragauskas

    2005-09-30

    The overall objective of this program was to develop improved extended oxygen delignification (EOD) technologies for current U.S. pulp mill operations. This was accomplished by: (1) Identifying pulping conditions that optimize O and OO performance; (2) Identifying structural features of lignin that enhance reactivity towards EOD of high kappa pulps; (3) Identifying factors minimizing carbohydrate degradation and improve pulp strength of EOD high kappa pulps; (4) Developing a simple, reproducible method of quantifying yield gains from EOD; and (5) Developing process conditions that significantly reduce the capital requirements of EOD while optimizing the yield benefits. Key research outcomes included, demonstrating the use of a mini-O sequence such as (E+O)Dkf:0.05(E+O) or Dkf:0.05(E+O)(E+O) without interstage washing could capture approximately 60% of the delignification efficiency of a conventional O-stage without the major capital requirements associated with an O-stage for conventional SW kraft pulps. The rate of formation and loss of fiber charge during an O-stage stage can be employed to maximize net fiber charge. Optimal fiber charge development and delignification are two independent parameters and do not parallel each other. It is possible to utilize an O-stage to enhance overall cellulosic fiber charge of low and high kappa SW kraft pulps which is beneficial for physical strength properties. The application of NIR and multi-variant analysis was developed into a rapid and simple method of determining the yield of pulp from an oxygen delignification stage that has real-world mill applications. A focus point of this program was the demonstration that Kraft pulping conditions and oxygen delignification of high and low-kappa SW and HW pulps are intimately related. Improved physical pulp properties and yield can be delivered by controlling the H-factor and active alkali charge. Low AA softwood kraft pulp with a kappa number 30 has an average improvement of 2% in yield and 4 cP in viscosity in comparison to high AA pulp for the oxygen delignification. This difference is also seen for high-kappa SW kraft pulps with an average improvement of {approx}3% in yield and 3 cP in viscosity for low AA high kappa number 50 pulp. Low AA hardwood kappa number 20 pulp had an average improvement of {approx}4% in yield and 6-12 cP in viscosity as compared to high AA pulp. Lower kraft cooking temperature (160 vs. 170 C) in combination with the medium AA provides a practical approach for integrating high kappa pulping of hardwoods (i.e., low rejects) with an advanced extended oxygen delignification stage. ECF pulp bleaching of low and high kappa kraft SW and HW pulps exhibit comparable optical and physical strength properties when bleached D(EPO)D.

  9. California high speed rail proposal: “High speed rail and wildlife”

    E-Print Network [OSTI]

    Wilkerson, Cynthia

    2005-01-01

    Chapter Wildlife and High Speed Rail C ALIFORNIA H IGH SDan Leavitt, California High Speed Rail Authority) AbstractThe California High Speed Rail (HSR) Proposal is in the

  10. Novel Refractory Materials for High-Temperature, High-Alkaline...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Applications Can be used in high-temperature, high-alkaline furnaces and process vessels found in aluminum, chemical, forest products, glass, and steel industries....

  11. Mesoporous Manganese Oxide Nanowires for High-Capacity, High...

    Office of Scientific and Technical Information (OSTI)

    Mesoporous Manganese Oxide Nanowires for High-Capacity, High-Rate, Hybrid Electrical Energy Storage Citation Details In-Document Search Title: Mesoporous Manganese Oxide Nanowires...

  12. High Temperature ESP Monitoring

    SciTech Connect (OSTI)

    Jack Booker; Brindesh Dhruva

    2011-06-20

    The objective of the High Temperature ESP Monitoring project was to develop a downhole monitoring system to be used in wells with bottom hole well temperatures up to 300°C for measuring motor temperature, formation pressure, and formation temperature. These measurements are used to monitor the health of the ESP motor, to track the downhole operating conditions, and to optimize the pump operation. A 220 ºC based High Temperature ESP Monitoring system was commercially released for sale with Schlumberger ESP motors April of 2011 and a 250 ºC system with will be commercially released at the end of Q2 2011. The measurement system is now fully qualified, except for the sensor, at 300 °C.

  13. High frequency reference electrode

    DOE Patents [OSTI]

    Kronberg, J.W.

    1994-05-31

    A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or halo' at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes. 4 figs.

  14. High frequency reference electrode

    DOE Patents [OSTI]

    Kronberg, James W. (Aiken, SC)

    1994-01-01

    A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or "halo" at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes.

  15. Ultra High Energy Fermions

    E-Print Network [OSTI]

    Burra G. Sidharth

    2015-04-07

    The LHC in Geneva is already operating at a total energy of $7 TeV$ and hopefully after a pause in 2012, it will attain its full capacity of $14 TeV$ in 2013. These are the highest energies achieved todate in any accelerator. It is against this backdrop that it is worthwhile to revisit very high energy collisions of Fermions (Cf. also \\cite{bgspp}). We will in fact examine their behaviour at such energies.

  16. High voltage pulse conditioning

    DOE Patents [OSTI]

    Springfield, Ray M. (Sante Fe, NM); Wheat, Jr., Robert M. (Los Alamos, NM)

    1990-01-01

    Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

  17. High current ion source

    DOE Patents [OSTI]

    Brown, Ian G. (1088 Woodside Rd., Berkeley, CA 94708); MacGill, Robert A. (645 Kern St., Richmond, CA 94805); Galvin, James E. (2 Commodore Dr. #276, Emeryville, CA 94608)

    1990-01-01

    An ion source utilizing a cathode and anode for producing an electric arc therebetween. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma leaves the generation region and expands through another regon. The density profile of the plasma may be flattened using a magnetic field formed within a vacuum chamber. Ions are extracted from the plasma to produce a high current broad on beam.

  18. High Performance Window Attachments

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12,ExecutiveFinancing ProgramsDepartment of¡High PerformancePerformance

  19. High pressure ceramic joint

    DOE Patents [OSTI]

    Ward, Michael E. (Poway, CA); Harkins, Bruce D. (San Diego, CA)

    1993-01-01

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

  20. High pressure ceramic joint

    DOE Patents [OSTI]

    Ward, M.E.; Harkins, B.D.

    1993-11-30

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 4 figures.

  1. High Energy Density Microwaves

    SciTech Connect (OSTI)

    Phillips, R.M. [Stanford Linear Accelerator Center, Stanford, CA 94309 (United States)

    1999-04-01

    These proceedings represent papers presented at the RF98 Workshop entitled `High Energy Density Microwaves` held in California in October, 1998. The topics discussed were predominantly accelerator{minus}related. The Workshop dealt, for the most part, with the generation and control of electron beams, the amplification of RF signals, the design of mode converters, and the effect of very high RF field gradients. This Workshop was designed to address the concerns of the microwave tube industry worldwide, the plasma physicists who deal with very high beam currents and gigawatts of RF power, and researchers in accelerator centers around the world. Papers were presented on multibeam klystrons, gyrotron development, plasmas in microwave tubes, RF breakdown, and alternatives to conventional linear coliders at 1 TeV and above. The Workshop was partially sponsored by the US Department of Energy. There were 46 papers presented at the conference,out of which 19 have been abstracted for the Energy,Science and Technology database.(AIP)

  2. High temperature interfacial superconductivity

    DOE Patents [OSTI]

    Bozovic, Ivan (Mount Sinai, NY); Logvenov, Gennady (Port Jefferson Station, NY); Gozar, Adrian Mihai (Port Jefferson, NY)

    2012-06-19

    High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La.sub.2CuO.sub.4) and a metal (La.sub.1-xSr.sub.xCuO.sub.4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, T.sub.c may be either .about.15 K or .about.30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, T.sub.c exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high T.sub.c phases and to significantly enhance superconducting properties in other superconductors. The superconducting interface may be implemented, for example, in SIS tunnel junctions or a SuFET.

  3. High energy physics

    SciTech Connect (OSTI)

    Kernan, A.; Shen, B.C.; Ma, E.

    1997-07-01

    This proposal is for the continuation of the High Energy Physics program at the University of California at Riverside. In hadron collider physics the authors will complete their transition from experiment UA1 at CERN to the DZERO experiment at Fermilab. On experiment UA1 their effort will concentrate on data analysis at Riverside. At Fermilab they will coordinate the high voltage system for all detector elements. They will also carry out hardware/software development for the D0 muon detector. The TPC/Two-Gamma experiment has completed its present phase of data-taking after accumulating 160 pb{sup {minus}}1 of luminosity. The UC Riverside group will continue data and physics analysis and make minor hardware improvement for the high luminosity run. The UC Riverside group is participating in design and implementation of the data acquisition system for the OPAL experiment at LEP. Mechanical and electronics construction of the OPAL hadron calorimeter strip readout system is proceeding on schedule. Data analysis and Monte Carlo detector simulation efforts are proceeding in preparation for the first physics run when IEP operation comenses in fall 1989.

  4. High Performance Computing School COMSC

    E-Print Network [OSTI]

    Martin, Ralph R.

    High Performance Computing School COMSC This module aims to provide the students with fundamental knowledge and understanding of techniques associated with High Performance Computing and its practical' skills in analysing and evaluating High Performance Computing and will be structured around

  5. High Energy Density Laboratory Plasmas

    E-Print Network [OSTI]

    High Energy Density Laboratory Plasmas General Plasma Science Developing founda/ons and advancing fundamental understanding #12;The High Energy Density developing innovative techniques to study the properties of instabilities in magnetized-high-energy-density

  6. Assessing Lanthanum-Bromide Detectors for Safeguards Applications

    SciTech Connect (OSTI)

    Gariazzo, Claudio Andres; Saavedra, Steven F; Smith, Steven E; Solodov, Alexander A

    2008-01-01

    Major detector technologies currently being used for gamma-ray spectroscopy in safeguards applications include systems based on sodium iodide (NaI), cadmium-zinc-telluride (CZT), cadmium-telluride (CdTe), and high-purity germanium (HPGe) crystals. Recently, a new scintillation detector based on a lanthanum bromide (LaBr3) crystal has become commercially available. The declared benefits of this new detector technology include higher resolution and improved efficiency compared with similarly configured NaI-based systems. Both detector systems offer the advantage of room-temperature operation. This paper describes the results of a study assessing the safeguards applicability and advantages for isotopic and quantitative analyses of uranium using the LaBr3-based detector, as well as an investigation into the general operating characteristics of the LaBr3-based detector. The results are compared with those from a widely used NaI-based detector system (Canberra's Inspector-1000 multichannel analyzer) operated under similar environmental conditions and hardware configuration, using commercially available software packages (NaIGEM and Genie-2000).

  7. Rain-Induced Increase in Background Radiation Detected by Radiation Portal Monitors

    SciTech Connect (OSTI)

    Hausladen, Paul; Blessinger, Christopher S; Guzzardo, Tyler; Livesay, Jake

    2012-07-01

    A complete understanding of both the steady state and transient background measured by Radiation Portal Monitors (RPMs) is essential to predictable system performance, as well as maximization of detection sensitivity. To facilitate this understanding, a test bed for the study of natural background in RPMs has been established at the Oak Ridge National Laboratory. This work was performed in support of the Second Line of Defense Program's mission to detect the illicit movement of nuclear material. In the present work, transient increases in gamma ray counting rates in RPMs due to rain are investigated. The increase in background activity associated with rain, which has been well documented in the field of environmental radioactivity, originates from the atmospheric deposition of two radioactive daughters of radon-222, namely lead-214 and bismuth-214 (henceforth {sup 222}Rn, {sup 214}Pb and {sup 214}Bi). In this study, rainfall rates recorded by a co-located weather station are compared with RPM count rates and High Purity Germanium spectra. The data verifies these radionuclides are responsible for the dominant transient natural background fluctuations in RPMs. Effects on system performance and potential mitigation strategies are discussed.

  8. Discrimination of gamma rays due to inelastic neutron scattering in AGATA

    E-Print Network [OSTI]

    A. Ataç; A. Ka?ka?; S. Akkoyun; M. ?enyi?it; T. Hüyük; S. O. Kara; J. Nyberg

    2009-06-10

    Possibilities of discriminating neutrons and gamma rays in the AGATA gamma-ray tracking spectrometer have been investigated with the aim of reducing the background due to inelastic scattering of neutrons in the high-purity germanium crystals. This background may become a serious problem especially in experiments with neutron-rich radioactive ion beams. Simulations using the Geant4 toolkit and a tracking program based on the forward tracking algorithm were carried out by emitting neutrons and gamma rays from the center of AGATA. Three different methods were developed and tested in order to find 'fingerprints' of the neutron interaction points in the detectors. In a simulation with simultaneous emission of six neutrons with energies in the range 1-5 MeV and ten gamma rays with energies between 150 and 1450 keV, the peak-to-background ratio at a gamma-ray energy of 1.0 MeV was improved by a factor of 2.4 after neutron rejection with a reduction of the photopeak efficiency at 1.0 MeV of only a factor of 1.25.

  9. Majorana Thermosyphon Prototype Experimental Results

    SciTech Connect (OSTI)

    Fast, James E.; Reid, Douglas J.; Aguayo Navarrete, Estanislao

    2010-12-17

    Objective The Majorana demonstrator will operate at liquid Nitrogen temperatures to ensure optimal spectrometric performance of its High Purity Germanium (HPGe) detector modules. In order to transfer the heat load of the detector module, the Majorana demonstrator requires a cooling system that will maintain a stable liquid nitrogen temperature. This cooling system is required to transport the heat from the detector chamber outside the shield. One approach is to use the two phase liquid-gas equilibrium to ensure constant temperature. This cooling technique is used in a thermosyphon. The thermosyphon can be designed so the vaporization/condensing process transfers heat through the shield while maintaining a stable operating temperature. A prototype of such system has been built at PNNL. This document presents the experimental results of the prototype and evaluates the heat transfer performance of the system. The cool down time, temperature gradient in the thermosyphon, and heat transfer analysis are studied in this document with different heat load applied to the prototype.

  10. Total and partial cross sections of the $^{112}$Sn($\\alpha,\\gamma$)$^{116}$Te reaction measured via in-beam $\\gamma$-ray spectroscopy

    E-Print Network [OSTI]

    Netterdon, L; Scholz, P; Zilges, A

    2015-01-01

    An extended database of experimental data is needed to address uncertainties of the nuclear-physics input parameters for Hauser-Feshbach calculations. Especially $\\alpha$+nucleus optical model potentials at low energies are not well known. The in-beam technique with an array of high-purity germanium (HPGe) detectors was successfully applied to the measurement of absolute cross sections of an ($\\alpha$,$\\gamma$) reaction on a heavy nucleus at sub-Coulomb energies. The total and partial cross-section values were measured by means of in-beam $\\gamma$-ray spectroscopy. Total and partial cross sections were measured at four different $\\alpha$-particle energies from $E_\\alpha = 10.5$ MeV to $E_\\alpha = 12$ MeV. The measured total cross-section values are in excellent agreement with previous results obtained with the activation technique, which proves the validity of the applied method. The experimental data was compared to Hauser-Feshbach calculations using the nuclear reaction code TALYS. A modified version of the...

  11. WDR-PK-AK-018

    SciTech Connect (OSTI)

    Hollister, R

    2009-08-26

    Method - CES SOP-HW-P556 'Field and Bulk Gamma Analysis'. Detector - High-purity germanium, 40% relative efficiency. Calibration - The detector was calibrated on February 8, 2006 using a NIST-traceable sealed source, and the calibration was verified using an independent sealed source. Count Time and Geometry - The sample was counted for 20 minutes at 72 inches from the detector. A lead collimator was used to limit the field-of-view to the region of the sample. The drum was rotated 180 degrees halfway through the count time. Date and Location of Scans - June 1,2006 in Building 235 Room 1136. Spectral Analysis Spectra were analyzed with ORTEC GammaVision software. Matrix and geometry corrections were calculated using OR TEC Isotopic software. A background spectrum was measured at the counting location. No man-made radioactivity was observed in the background. Results were determined from the sample spectra without background subtraction. Minimum detectable activities were calculated by the Nureg 4.16 method. Results - Detected Pu-238, Pu-239, Am-241 and Am-243.

  12. Cross-section measurement of the $^{130}$Ba(p,$?$)$^{131}$La reaction for $?$-process nucleosynthesis

    E-Print Network [OSTI]

    L. Netterdon; A. Endres; G. G. Kiss; J. Mayer; T. Rauscher; P. Scholz; K. Sonnabend; Zs. Török; A. Zilges

    2014-09-27

    A measurement of total cross-section values of the $^{130}$Ba(p,$\\gamma$)$^{131}$La reaction at low proton energies allows a stringent test of statistical model predictions with different proton+nucleus optical model potentials. Since no experimental data are available for proton-capture reactions in this mass region around A~$\\approx$~130, this measurement can be an important input to test the global applicability of proton+nucleus optical model potentials. The total reaction cross-section values were measured by means of the activation method. After the irradiation with protons, the reaction yield was determined by use of $\\gamma$-ray spectroscopy using two clover-type high-purity germanium detectors. In total, cross-section values for eight different proton energies could be determined in the energy range between 3.6 MeV $\\leq E_p \\leq$ 5.0 MeV, thus, inside the astrophysically relevant energy region. The measured cross-section values were compared to Hauser-Feshbach calculations using the statistical model codes TALYS and SMARAGD with different proton+nucleus optical model potentials. With the semi-microscopic JLM proton+nucleus optical model potential used in the SMARAGD code, the absolute cross-section values are reproduced well, but the energy dependence is too steep at the lowest energies. The best description is given by a TALYS calculation using the semi-microscopic Bauge proton+nucleus optical model potential using a constant renormalization factor.

  13. Role of p-induced population of medium mass(A $\\sim$ 150) neutron rich nuclei

    E-Print Network [OSTI]

    D. Banerjee; A. Saha; T. Bhattacharjee; R. Guin; S. K. Das; P. Das; Deepak Pandit; A. Mukherjee; A. Chowdhury; Soumik Bhattacharya; S. Das Gupta; S. Bhattacharyya; P. Mukhopadhyay; S. R. Banerjee

    2014-12-24

    Excitation functions were measured by stacked-foil activation technique for the $^{150}$Nd(p, xpyn) reaction using 97.65$%$ enriched $^{150}$Nd target. Measurement up to $\\sim$50$%$ above barrier and down to 18$%$ below the barrier was performed using proton beam energy (E$_p$) of 7 - 15 MeV from VECC Cyclotron. The yield of suitable $\\gamma$ rays emitted following the decay of relevant evaporation residues was determined using a 50$%$ High Purity Germanium (HPGe) detector.(p,n) cross section was found to follow the expected trend with a maximum value of 63.7(4.9)mb at E$_p$ $\\sim$ 8.6 MeV. (p,2n) cross section gradually increased with E$_p$ and had maximum contribution to the total reaction cross section after E$_p$ $\\sim$ 9.0 MeV. (p, p$^{\\prime}$n) reaction channel also showed a reasonable yield with a threshold of E$_p$ $\\sim$ 12.0 MeV. The experimental data were corroborated with statistical model calculations using different codes, viz., CASCADE, ALICE/91 and EMPIRE3.1. All the calculations using a suitable set of global parameters could reproduce the excitation function fairly well in the present energy range.

  14. High mobility high efficiency organic films based on pure organic materials

    DOE Patents [OSTI]

    Salzman, Rhonda F. (Ann Arbor, MI); Forrest, Stephen R. (Ann Arbor, MI)

    2009-01-27

    A method of purifying small molecule organic material, performed as a series of operations beginning with a first sample of the organic small molecule material. The first step is to purify the organic small molecule material by thermal gradient sublimation. The second step is to test the purity of at least one sample from the purified organic small molecule material by spectroscopy. The third step is to repeat the first through third steps on the purified small molecule material if the spectroscopic testing reveals any peaks exceeding a threshold percentage of a magnitude of a characteristic peak of a target organic small molecule. The steps are performed at least twice. The threshold percentage is at most 10%. Preferably the threshold percentage is 5% and more preferably 2%. The threshold percentage may be selected based on the spectra of past samples that achieved target performance characteristics in finished devices.

  15. High Performance Computing Center IT DIVISION -HIGH PERFORMANCE COMPUTING CENTER

    E-Print Network [OSTI]

    Rock, Chris

    . It will ensure that Texas Tech retains superior computing and visualization facilities. #12;High PerformanceHigh Performance Computing Center 9/27/2004 1 IT DIVISION - HIGH PERFORMANCE COMPUTING CENTER STRATEGIC PLAN MISSION STATEMENT The High Performance Computing Center (HPCC) promotes research and teaching

  16. High Availability for High-End Scientific A Dissertation

    E-Print Network [OSTI]

    Engelmann, Christian

    High Availability for High-End Scientific Computing A Dissertation Submitted In Partial Fulfilment in the area of high availability is essential to meet the needs to sustain the current growth. This thesis introduces a new approach to high availability which focuses on the head node of a cluster system

  17. Infrared spectroscopic and modeling studies of H{sub 2}/CH{sub 4} microwave plasma gas phase from low to high pressure and power

    SciTech Connect (OSTI)

    Rond, C. Lombardi, G.; Gicquel, A.; Hamann, S.; Röpcke, J.; Wartel, M.

    2014-09-07

    InfraRed Tunable Diode Laser Absorption Spectroscopy technique has been implemented in a H{sub 2}/CH{sub 4} Micro-Wave (MW frequency f?=?2.45 GHz) plasma reactor dedicated to diamond deposition under high pressure and high power conditions. Parametric studies such as a function of MW power, pressure, and admixtures of methane have been carried out on a wide range of experimental conditions: the pressure up to 270 mbar and the MW power up to 4?kW. These conditions allow high purity Chemical Vapor Deposition diamond deposition at high growth rates. Line integrated absorption measurements have been performed in order to monitor hydrocarbon species, i.e., CH{sub 3}, CH{sub 4}, C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, and C{sub 2}H{sub 6}. The densities of the stable detected species were found to vary in the range of 10{sup 12}–10{sup 17} molecules cm{sup ?3}, while the methyl radical CH{sub 3} (precursor of diamond growth under these conditions) measured into the plasma bulk was found up to 10{sup 14} molecules cm{sup ?3}. The experimental densities have been compared to those provided by 1D-radial thermochemical model for low power and low pressure conditions (up to 100 mbar/2?kW). These densities have been axially integrated. Experimental measurements under high pressure and power conditions confirm a strong increase of the degree of dissociation of the precursor, CH{sub 4}, associated to an increase of the C{sub 2}H{sub 2} density, the most abundant reaction product in the plasma.

  18. HIGH EFFICIENCY SYNGAS GENERATION

    SciTech Connect (OSTI)

    Robert J. Copeland; Yevgenia Gershanovich; Brian Windecker

    2005-02-01

    This project investigated an efficient and low cost method of auto-thermally reforming natural gas to hydrogen and carbon monoxide. Reforming is the highest cost step in producing products such as methanol and Fisher Tropsch liquids (i.e., gas to liquids); and reducing the cost of reforming is the key to reducing the cost of these products. Steam reforming is expensive because of the high cost of the high nickel alloy reforming tubes (i.e., indirectly fired reforming tubes). Conventional auto-thermal or Partial Oxidation (POX) reforming minimizes the size and cost of the reformers and provides a near optimum mixture of CO and hydrogen. However POX requires pure oxygen, which consumes power and significantly increases the cost to reforming. Our high efficiency process extracts oxygen from low-pressure air with novel oxygen sorbent and transfers the oxygen to a nickel-catalyzed reformer. The syngas is generated at process pressure (typically 20 to 40 bar) without nitrogen dilution and has a 1CO to 2H{sub 2} ratio that is near optimum for the subsequent production of Fisher-Tropsch liquid to liquids and other chemicals (i.e., Gas to Liquids, GTL). Our high process efficiency comes from the way we transfer the oxygen into the reformer. All of the components of the process, except for the oxygen sorbent, are commonly used in commercial practice. A process based on a longlived, regenerable, oxygen transfer sorbent could substantially reduce the cost of natural gas reforming to syngas. Lower cost syngas (CO + 2H{sub 2}) that is the feedstock for GTL would reduce the cost of GTL and for other commercial applications (e.g., methanol, other organic chemicals). The vast gas resources of Alaska's North Slope (ANS) offer more than 22 Tcf of gas and GTL production in this application alone, and could account for as much as 300,000 to 700,000 bpd for 20 to 30+ years. We developed a new sorbent, which is an essential part of the High Efficiency Oxygen Process (HOP). We tested the sorbent and observed that it has both a good oxygen capacity and operates as a highly effective reforming catalyst. We conducted a long duration tests of the sorbent (1,500 hours of continuous operation in the HOP cycle). Although the sorbent lost some oxygen capacity with cycling, the sorbent oxygen capacity stabilized after 1,000 hours and remained constant to the end of the test, 1,500 hour. The activity of the catalyst to reform methane to a hydrogen and carbon monoxide mixture was unchanged through the oxidation/reduction cycling. Our cost and performance analyses indicated a significant reduction in the cost of GTL production when using the HOP process integrated into a GTL plant.

  19. Theoretical High Energy Physics

    SciTech Connect (OSTI)

    Christ, Norman H.; Weinberg, Erick J.

    2014-07-14

    we provide reports from each of the six faculty supported by the Department of Energy High Energy Physics Theory grant at Columbia University. Each is followed by a bibliography of the references cited. A complete list of all of the publications in the 12/1/2010-04/30/2014 period resulting from research supported by this grant is provided in the following section. The final section lists the Ph.D. dissertations based on research supported by the grant that were submitted during this period.

  20. High speed flywheel

    DOE Patents [OSTI]

    McGrath, Stephen V. (Knoxville, TN)

    1991-01-01

    A flywheel for operation at high speeds utilizes two or more ringlike coments arranged in a spaced concentric relationship for rotation about an axis and an expansion device interposed between the components for accommodating radial growth of the components resulting from flywheel operation. The expansion device engages both of the ringlike components, and the structure of the expansion device ensures that it maintains its engagement with the components. In addition to its expansion-accommodating capacity, the expansion device also maintains flywheel stiffness during flywheel operation.